Threading Information, New Atlas Six-Inch Lathes

8/4/2019 Threading Information, New Atlas Six-Inch Lathes

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THISBOOKcontains complete informationessential for handling thread cutting andcoil winding operations on the new AtlasSix-inchLathes (Catalog Nos. 612 and 618).

,1('.; L iJ/t?o/2. 0" (1/ch !;!Ii/IV

T HR EA D C U TT IN GON THE NEW ATLAS SIXINCH LATHE

No phase of lathe operation is more interesting or profitablethan the cutting of screws and threads; and no operation re-quires more care and study. The thread cutting range of the Atlasis practically unlimited-a few sample threads are shown in Fig. 1.This section deals with the two classes of thread cutting

problems: (1) those connected with the change gear train and itsproper set-up for cutting the various sizes of threads. and (2) theactual cutting of the many thread forms.

FIG. 1. A few of the threads that can be cut on the lath e,Every Atlas lathe comes equipped with change gears and

threading dial for cutting threads in the following standards:National Coarse (U.S.S.), ,National Fine (S.A.E.), Acme, Square,and Whitworth. Gear set-ups for standard threads are shown onthe pictorial threading chart on the inside of the change-gear guard(Fig. 2). Figure 4 is an actual-size reproduction of this threadingchart. Gear data for odd-size threads are given i n Table I, page 38.An attachment (No. M6-735) is available to cut standard metricthreads from .5 to 3 mm.

3


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4 MANUAL OF LATHE OPERATION/

FIG. 2Left en d of lathe with gear guardopen, showing change 'gears, gear tra in,and loca ti on of th read ing cha rt.

READING THE GEAR CHARTSTo simplify gear set-ups, the three different gear bracket posi-

tions have been assigned letters as shown in Figure 3. Thesedesignations will be found on the lathe threading chart as well asin all of the following gear data.

POSITION APOSITION B

FIG. 3. Gea r bracket positions.The outer end of the longest bracket slot is called "Position A,"

the inner portion of the same slot is "Position B." The short slotadjacent to the long slot i s Position "C." These gear positions areapproximate-they will vary with the size' and number of the gearscomposing the train (see diagrams in Fig. 4 and on the followingpages).

SLEEVE AND BUSHING ASSEMBLYBefore setting up a train of change gears, examine one of the

sleeve and bushing assemblies which hold the change gears to thegear bracket (Fig. 5). Each sleeve is long enough to accommo-date two gears and has a double key which fits into the keyways inthe gears. The sleeve and two gears fit over a bushing, and th ;assembly is bolted to the gear bracket. The washer is .a bearingfor the outer end of the sleeve.

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THREAD CUTTING

THREADING CHART FOR ATLAS 6-INCH LATHES

gJ I . SPINDlE T H R E A D I N G C H A R TII !6_8 A -B -C A RE G EA R S TU D P OS IT IO NS3,.2 SC REW B ::. BA C K P OS IT IO N ( TO WA RD H EA D ST DC K )SPACER -~-;l-_:_~i~~.J-.;~ f =fR D NT PO SIT IO N (A WA Y fR OM H E AD S TO C K)S EH PFO R :- ....w i c t 4 Q I= IO LE R G EA R -=BLANKS-16 THRUDS I l i l 9 J c s = S P A C E R G E A R X X S = S T EE L S P A C E R

rn:. ::II l ".'SPINDLE . T ilR EA DS G EA RO N P OS IT IO N C P DS lT U1 N B P OS IT IO N A S PIN DL E F IG::::: ==.I ".... PE R I N C R S CR EW B F B F B F S T U D G E A R '~. !6 832f 32 64 - - 64 IXXS 32 II 3 2 S C R E W t - -= -+ :~+ :==-= - : -+ - - - -1~~=+~-= - - . f - ! " ' - I6 4.(':iI_: -- ':: _~ 9 36 f 3264 - - 641XXS 32 I

S PAC E R - _ - ' i "_i- ~ 10 40f 32 64 - - 641 XXS 32 Isn'U P FO R ::;~ "44F 20 40 - - 64 1 XIS 32 IIS-32THRUOS 1 1 . 5 46F 20 40 54 ! X IS 32 I

g)FIG.3 0 SPIHDLI 12 48F 2040 - - 64[IX5 32 Io. 16 1 3 52f 2040 - - 6 41XXS 32 I

64 00 32 S C R E W 14 56F 20 40 - - 64 1 XXS 32 1S PAC ER ~ - - _: ; s .~ ' i ! I 16 64F 20 40 - - 641XXS 32 I

SE T - U PFDR " '1 i i i i i i I . \ ~ ~ . . -2"1!i3t 18 368 - - 641XXS - - 32 2~AD S ~2 !1 20 408 - - 641 X XS - - 32 2

22 448 - - 64 1 XXS - - 32 224 488 - - 641 XXS - - 32 227 548 - - 641 XXS - - 32 228 56B - - 54IXXS - - 32 232 64B - - 6 41XXS - - 32 236 36F 2 0 S 3 2 1 - - XXS641 16 3

g F ' G . 4116 4 32 W

SH HPfDR~A 40 40 F 2 0 S 321 XXS 6 4 1 16 3

44 44F 2 0 S 321 - - X IS 6 41 16 348 48f 2 0 S 321 - - X X S 54 1 16 356 56F 2 0 S 321 - - X X S 641 16 36 4 64F 2 0 S 321 - - XX5641 16 372 36B 56 ] X X S - - 32 64 16 480 40 8 5&1XXS 32 64 16 4

! ! ! J F! G . 5 I;;ISPINDlf~ . ! 5r ~3;2 S C R EW

48 I ~ ; > i " ; ~ l o ~4 iii! ,o j , " . ! " . . Jsn'U P FO R ~ 6 4O D 39' FE ED 3Z

l i m n in G 6 1 rr.:ij 32= = tt~SfIHDL( 96 488 5 6 J XXS - - 64 16 4~.:~.6 F E E D P E R R E V O L U T IO N O F S P IN D L El4~ ..~ == J.3~...S C R E W .0024" 64F 64 20 24 48 16 5

4 8 :1 i ii ii i ii i ii ii . \ ~ '- , , . r ; I~~0039 " 64 F 64 32 - - 24 48 16 5SH-UPFOR ,,~< 64 .0048" 6 48 20 64 - - 48 24 32 6~D 20 .0078" 64 8 32 64 - - 48 24 32 6

FIG. 4. Thread ing cha rt for cut ting s tanda rd threads between 8 and 96 per inch.For additional gear train data, refer to Table I. page 38 .

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6 MANUAL OF LATHE OPERATION

NUTBOLT

SLEEVE)FIG. 5. C ross s ec tion of s le eve and bush ing as sembly.Notice that in order to make this assembly complete, two gears

must be mounted on the sleeve at one time. When both of thegears on a sleeve mesh with other gears in the train, they form a"compound" gear assembly. When only one of two gears on asleeve meshes with the other gears in the train, it is called an"idler." The smaller gear, which is mounted on the sleeve with anidler, is called a "spacer" gear and does not mesh with any gear inthe train (see Fig. 10).

GEAR CLEARANCE

CLEARANCE

When setting up thegear train, be sure to al-low sufficient clearance

CLEARANCE between two meshinggears (Fig. 6). Gear

clearance does not reducethe accuracy of a thread cut-

ting operation, because all playin the gears is taken up in one di-

rection. A method often used to ob-F I G . 6Proper gear clearance. tain proper gear clearance is: (1) Place

a sheet of thick writing paper between the teeth of the two meshinggears, (2) tighten gears in position, and (3) remove paper. A smallamount of grease, preferably graphite grease, applied to gear teethwill often aid in obtaining smoother, more quiet operation.

l.

THE REVERSING MECHANISMRight hand threads are cut with the carriage traveling toward

the headstock. Left hand threads are cut with the carriage travel-ing toward the tailstock.

Whenever a new gear train has been set up, shift the tumblergear lever to test the direction of the carriage travel. Because s?meset-ups are simple-geared and some are compounded, the carnagetravel may be to the right for one set-up and to the left for anotherset-up, even though the lever is shifted to the same position in eachcase. Always test the direction of carriage travel before startingto cut a thread.

" I

THREAD CUTTI NG 7

After the tumbler gear lever has been shifted to the proper posi-tion, it should not be moved until the thread has been completed.This is especially important because a shift in the lever positi'ondestroys the relation between the threading dial and the lathespindle and causes splitting of the thread.

GEAR TRAINS FOR STANDARD THREADSThe following pages give detailed instructions for mountinggears for the more common thread sizes. Refer to these pages and

the lathe threading chart when making set-ups. "Back Position". of ,a sleeve or the screw stub means the position toward the headstock."Front Position" is the position away from the headstock. Thegear bracket is tightened in position by locking the nut on the frontof the gear bracket.

.'.."..1J.

32 TOOTH GEARGEAR TRAIN FOR 8 THROUGH 10 THREADS PER INCH/ 1. Place on front position of screw stub the gear listed in"'Gearon Screw" column of threading chart.

2. Place 32 tooth gear and 64 tooth gear on sleeve and mountin Position C on gear bracket with 32 tooth gear in back position.Tighten so that 64 tooth gear meshes with gear in screw position.

3. Place 64 tooth gear and spacer on a sleeve and mount inPosition A with 64 tooth gear in back position. Tighten so that64 tooth gear meshes with the 32 tooth gear in Position. C. The64 tooth gear is an idler.4. Swing entire gear bracket upward and tighten so that 64

tooth gear in Position A meshes with the 32 tooth compoundtumbler gear.


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10 THREAD CUTTINGANUAL OF LATHE OPERATION

GEAR TRAIN FOR 36 THROUGH 64 THREADS PER INCH(See Fig. 10, page 9.)

1. Place in front position of screw stub the gear listed in "Gearon Screw" column of threading chart.

2. Place 20 tooth gear and 32 tooth gear on sleeve and mountin Position C with 20 tooth gear in back position. Tighten so that32 tooth gear meshes with gear in screw position. The 32 toothgear is an idler; the 20 tooth gear is a spacer.

3. Place spacer and 64 tooth gear on sleeve and mount in Posi-tion A with spacer in back position. Tighten so that 64 tooth gearmeshes with 32 tooth gear in Position C. The 64 tooth gear is anidler.

4. 'Swing entire gear bracket upward so that the 64 tooth gearin Position A meshes with the 16 tooth compound tumbler gear.

3. Place 64 tooth gear and 32 tooth gear on sleeve and mountin Position A with 32 tooth gear in back position. Tighten so that32 tooth gear meshes with 56 tooth gear in Position C.

4. Swing entire gear bracket upward and tighten so that the64 tooth gear in .Position A meshes with the 16 tooth compoundtumbler stud gear.

THREAD CUTTING TERMSPITCH11 .. .

IGEAR TRAIN FOR 72 THROUGH 96 THREADS PER INCH

FI G. 13. Thread Cutting Terms.

TOOTH GEAR MAJOR DIAMETER-The largest diameter of the thread ofeither the screw or the nut.

MINOR DIAMETER-The smallest diameter of 'the threadof either the screw or the nut.

PITCH DIAMETER-On a straight screw thread, the diam-eter of an imaginary cylinder, the surface of which would" passthrough the threads at such points as to make equal the width ofthe threads and the width of the spaces cut by the surface of thecylinder. In Figure 13 the lines representing the diameter "PD,"are located so as to make spaces "aa" and "bb" equaL On a 60

~ Vee-type thread and on National Form threads, the pitch diameteris simply the major diameter less the depth of the thread.

STEELSPACER

FIG. 11. Gear set-up for 72 and 80 threads per inch.

1. Place in back position of screw stub the gear listed in "Gearon Screw" column of threading chart.2. Place 56 tooth gear and spacer on sleeve and mount in Posi-

tion C with 56 tooth gear in back position. Tighten so that 56tooth gear meshes with the gear in screw position. The 56 toothgear ~san idler.

DEPTH OF THREAD-One-half the difference between themajor diameter and the minor diameter. In lathe work, theDOUBLE DEPTH OF THREAD, which is the difference be-

11


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12 MANUAL OF LATHE OPERATION TH READ CUTTI NG 13tween the major and mmor diameters, is a quite common term.Thus, knowing the major diameter required, subtracting from itthe double depth of thread for the required pitch, gives the minordiameter. A table giving double depths of National Form threadsfor different pitches will be found on page 42.

THREAD CUTTING TOOLSThread cutting tools must be ground to the form of thread

desired. Clearance must be increased because of the rapid advance

FIG. 15"A" shows t oo l w ithsufficient clearance.When thread pitch isincreased, as at F 4 S . "same tool has inade-quate clearance.

PITCH-The distance from a point on a screw thread to a. corresponding point on the next thread, measured parallel to theaxis (see Fig. 13).

1P = Pitch of thread in inches = -----------. . Number of threads per inchIII I. '

BTHREADS PER INCH-The number of complete threads in

the space of one inch. In Figure 13, the distance between pointsX and Y represents one inch, and there are five threads per inch.

1n = Number of threads per inch = ---pitch

of the tool. Otherwise the grinding of thread cutting tools fol-lows the same general rules as the grinding of external tools .Clean, accurate threads are impossible unless one side and the

front of the tool are given enough clearance to permit the tool toadvance as the work revolves. Figure 15 shows how a toolwhich is satisfactory for cutting a fine thread may not haveenough clearance to cut a coarse thread. "Hogging" and roughthreads are usually the result of insufficient clearance.

Thread tools are ground nearly flat across the top. When thetool is fed into the work at an angle, as with National Formthreads, the tool should have a few degrees of side rake. Whenthe tool is fed into the work at right angles, as with squarethreads, it should have a small amount of back rake.

LEAD - The dis-tance a screw threadadvances axially in oneturn. On a singlethread screw, the leadand the pitch are iden-tical; on a doublethread screw, the leadis twice the pitch; on atriple thread screw thelead is three times thepitch, et~.Figure 14 shows a

double thread screw.There are two separate grooves or helices around the screw, eachof which advances twice the pitch in a single turn. Ifthe pitch of

CUTTING 60 TYPE THREADS

~ FIG. 14Double Thr d Screw. The lead i8 double the p it ch .

I 'this screw is ? i inch, the lead is 7 4 inch, D=.866 x PFIG. 16. 600 Vee Thread and Fo rmula (see p age 14).


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I I

1 4 MANUAL OF LATHE OPERATION THREAD CUTTI NG 1 5NATIONALFORM NUT

that the depth is 75% of the depth of a Vee thread of the same pitch.Figure 18,shows a tool bit ground for cutting sharp pointed Vee

threads. This tool will also cut an exact National Form Screwthread when the point is ground Hat to fit the proper slot in theNational Form thread gauge (Fig. 19). Generally, however, thetool is left sharp pointed and the thread is cut with the regulationVee bottom, but the top is left with the proper amount of flat. Fig-ure 20 shows how a screw cut in this manner fits a National Formnut. Only when desiring ab-solute maximum strength isthe tool ground to the exactNational Form.The screw pitch gauge

shown in Figure 21 is used todetermine the exact pitch of aV -thread screw or nut. This FIG, 22. Threading Toolgauge has thirty separate leaves with pitches between 4 and 42per inch.

THREADS CUTWITH V TOOL

D= .64952 x P f= ~FIG. 17. American Nat iona l 0[ Nat ional Form Thread and Formulas .

60 degree type threads include the 600 Vee thread (Fig. 16) andthe American National Screw Thread (Fig. 17). The 600 Veethread is cut very seldom, usually for small screws where the flat at

A

:!p1J TOP SAFIG, 20The National Form nut fits the screwcut with a 600 Vee tool.

FIG. 21Nat ional Scr ew Pi tch Gauge ,

51DE CLEARANCE8. TO 150 FIG. 18., Tool far cutting 600 type threads. THREADING TOOLThe threading tool shown in Figure 22 has become extremelypopular because it can be used to cut all pitches of National Formthreads with the slight difference in form mentioned above.

FIG. 23Prop e r method ofgrinding t he thread-ing tool shown in Fig-ure 22. The side fac-es are never ground.

FRONT

the top and bottom of the National Form Thread would be so small. that it approaches the Vee form. Small

taps usually produce Vee-type threads,and the resulting holes accommodate thestandard National Form Screws.

The American National Screwthreads, (National Fine and NationalCoarse) are practically standard for au-tomotive and machine shop work in theUnited States. These threads are 60Vee threads with the points cut off soFIG. 19. N. F. Thread Gauge.

GRINDING WHEEL

GRINDTOP EDGEONLY


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1 6 MANUAL OF LATHE OPERATION

The sides of this tool are ready ground to an included angle ofapproximately 65 degrees. The extra S compensates for rake angleand the grinding of the tool-a perfect 60 thread is produced when

,:+ the tool is set into the work properly (see page 17). The form of,1jhistool also provides ample clearance for even the coarsest threads.,The tool is resharpened by simply grinding the top edge, adjustingthe tool as it wears.

"'D"TURNED TO SAMEDIAMETER AS ~C N" c "TURNED TOMINOR DIAMETER

FIG. 24PREPARING THE WORK FOR AN EXTERNAL

60 NATIONAL FORM THREADThe work to be threaded is first turned to the exact major di-

ameter of the desired thread. The beginner often finds it helpful toturn the grooves C and D(Fig. 24) to the exact minordiameter. The size of theminor diameter depends up-on the form of the threadingtool. If the thread is to becut with a sharp pointeden?tool, the minor diameter isequal to the major diameterless the Vee-Form DoubleDepth of Thread (Table IV,page 42) or the major diam-eter less 1.732 X pitch. If atool bit has been formed es-pecially for a National Formthread, the correct minor

FIG. 25Correct settinlt of tool and compoundrelt when cuttinr a 800 t il [ht hand thread.

THREAD CUTTING 17

diameter is listed in Table V or Table VI, pages 43 and 44 (majordiameter less 1.299 X pitch).

Groove C permits accurate measurement with a micrometer ofthe bottom of the thread. When the tool point has cut to the depthof the groove C, the thread has been finished. Groove D permitsthe work to revolve freely at the end of each cut. As soon as thebeginner has become a little more familiar with threading practice,these grooves can be omitted.

FIG, 26. Center Gauge.

FIG. 27 (Right)Using the center gauge (0set the threading tool at anexact right anglo to thework.

SETTING THE 60 THREADING TOOLAfter the work has been properly prepared for threading, set

the compound rest at the 29 angle shown in Figure 25. Mountthe tool holder in the tool post so that the point of the tool is exact-lyon the lathe center line-tighten tool post screw just enough tohold the tool holder. Then use a center or thread gauge (Fig. 26)to set the tool point at an exact right angle to the work as shownin Figure 27. Tap lightly on the back of the tool holder whenbringing it into position. A piece of white paper placed under thecenter gauge will aid in checking the fit of the tool in the Vee ofthe gauge. With the tool point at an exact right angle to the work,recheck the center line position and tighten tool post screw.

THE CUTTING OPERATIONBefore starting the actual cutting of a right hand thread, be

sure that the change gear train is assembled properly and that thereverse lever is in the correct position to feed the carriage towardthe headstock'. Adjust belts for a speed of 54 R.P.M. (see Instruc-tions and Parts List, page 1).

Set the compound rest approximately in the center of its ways


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18 MANUAL OF LATHE OPERATION THREAD CUTTING 1 9THE THREADING DIAL

The threading dial (Figs. 28 and 29)performs an important function by indicatingthe proper time to engage the half-nut lever sothat the tool will enter the same groove of thethread for each. cut. Without the threadingdial it would be necessary to reverse the motorat the end of each cut and "wind the tool outof the thread - a cumbersome method littleused except when cutting metric and specialfractional threads (page 28).

RULES FOR THE USE OF THE THREADING DIALWhen cutting an even-numbered thread (such as 12, 14, 16, 32,

etc. per inch), engage the half-nut lever for the first cut when thestationary mark on the outside of the threading dial is in line withanyone of the four markson the rotating portion ofthe dial. The same dialmarking, or the one oppo-site, must be used for fol-lowing cuts.When cutting odd-num-

bered threads (such as 9,11, 13, 27, etc. per inch) andh al f-m um b ered threads(such as 8 Y z , 9%, 1 0 Y z , etc.per inch), engage the half-nut lever at the same markon the threading dial foreach cut.

CUTTING INTERNAL 60 NATIONAL SCREW THREADSThe tool shown in Figure 30 is designed for cutting internal

60 form threads and is mounted directly in the tool post exactly

and advance the cross feed so that it is set at with the tool closeto the work. With the point of the tool about an inch to the right.of the start of the thread, advance the tool with the compound restso that the first cut will be about .003 inch.

Start the lathe and engage the half-nut lever on the carriage asdescribed on page 19. The 29 angle of the compound rest shouldallow the back of the tool to take a fine chasing cut on the finishedside of the thread while the cutting edge does the work of formingthe thread. Apply plenty of lubricant to the work. When thepoint of the tool reaches the groove at the end of the thread (grooveD in Figure 24), raise the half-nut lever on the carriage. back outthe cross feed a turn or two, and return the carriage by hand tothe starting point. Advance the cross f:ed to its original positionat 0, advance the compound rest for the desired depth of cut, andengage the half-nut lever for the second cut. All feeding is donewith the compound rest. Follow the same routine on all succeed-ing cuts.

FIG. 28Threading DiaL

DEPTH OF CUT: The first two or three cuts ~hould be ap-proximately .005 inch advance of the compound feed and the fol-lowing cuts gradually reduced until the last few cuts taken areonly .001 inch or even .0005 inch. A final pass through the threadwith no advance whatever will often clean up any remaining highspots. Take the last cuts with extreme care. Heavier cuts can betaken on soft metals such as brass or aluminum, but if a fine finishis desired, the last cuts should be very light.

LUBRICANTS: When cutting steel use liberal quantities of acommercial cutting compound, lard oil or equivalent. With othermetals use the type of lubricant recommended for general turningoperations.

THREAD CUTTING SPEEDS: The beginner in thread cut-ting should adjust belts to obtain a speed of 54 R.P.M. (Instructions,page 1). This slow speed allows plenty of time to engage anddisengage the half-nut lever. After more experience in cutfingthreads, higher speeds can be used up to approximately 1/3 or1/2 the speeds recommended for turning the various materials.

FIG. 29'I 'br eading' dial showing rnalnmarkings.Other lines may be marked in by theoperator as needed.


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2 0 M A N U A L ' O F L A TH E O P E R A T IO N

like a boring tool. The angles shown are typical and sat-isfactory for threads as

E N . D coarse as 12 per inch andholes as small as % inch.The point is ground to 60and has a slight side rake

as shown in the front view.It is very important to haveplenty of front fwd side clearance-much more important than withthe plain boring tool, The pointof the tool is set exactly on thecenter line of the work.

.0TOP

( I fFRONT

FIG, 30Tool for cut ting internal 600 threads.(When threading brass and plast ics,omit s ide rake.)

PREPARING THE WORK FOR INTERNALNATIONAL FORM THREADS

Work to be threaded internally is prepared much in the samemanner as for cutting an external thread (see page 16). The workis first bored to the exact minor diameter. Beginners often turngrooves C and, D to the exact major diameter as shown in Figure

PRECAUTIONS IN CUTTING THREADSNever disengage the .half-nut lever in the middle of the threadwithout first hacking out the tool with the cross feed.Do not shift the tumbler gear lever until the thread is com-pleted.If the work must be removed for checking the fit of a cut orfor any other reason, be sure to replace the work with the tailof the lathe dog in the same slot of the face plate as belore.Never remove work held in a. chuck until the thread is com-pleted.When a long, heavy thread is being turned, considerable heatmay be generated, causing the work to expand. If the work ismounted between centers, stop the lathe at regular intervalsand check the tightness 01 the work against the centers. Takea light cut after checking in this way, because the work mayhave shifted a trifle in relation to the position 01 the tool bit.If the tool has a tendency to "hog in," check tool clearance.

T H R E A D C U T T I N G 2 1

31. If the thread is to be cut with a sharp pointed 60 tool, themajor diameter is equal to the minor diameter plus the Vee-formDouble Depth of Thread(Table IV, page 42). Ifthe tool bit is formed es-pecially for a certain Na-tional Form thread, thecorrect major diameter islisted in Table V or Ta-ble VI, pages 43 and44.

Groove C permits the

WORK Iu,a ::o .z 1 "-0:lWORKFIG. 31

Grooves C and D help the beginner whenthreading internally.beginner to measure ac-curately the bottom of the thread with a micrometer or caliper andserves as a guide for depth. When the tool point has cut to thedepth of groove C, the thread has been finished. This outer groove

is not necessary if the thread is being cut to fit a certain screw-the proper depth is then reached when the screw fits the threadcorrectly.

Groove D should be about twice as wide as the thread pitchand a few thousandths larger than the major diameter. Thisgroove provides a brief interval at the end of each cut during whichthe work can revolve freely while the half-nut lever is disengaged.The grooves C and D can be omitted after the operator has learnedinternal thread cuttin.g operations.

FIG. 32Correct setting of thetool and compound restfor internal threading.The point of the tool isset on the exact centerline.

COMPOUNDTO B E S E T

AT 290


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22 THREAD CUTTING 23MANUAL OF LATHE OPERATION

CUTTING INTERNAL THREADS CUTTING ACME THREAD'SThe internal cutting operation is the same as the cutting of an

external thread (page 17), with the following exceptions: First,the 29 angle of the compound rest is measured from the oppositeside of the graduated base (Fig. 32).

Second, the compound rest feed is toward the operator forcutting and the cross feed is advanced to clear the work.Due to the spring of an internal tool, cuts should be muchlighter than when cutting external threads. The last finish cutsshould be taken without changing the setting of the compound rest. D=-f+.OIO F.3707xPW=..3707x P -.0052" MINOR DIA MAJOR DIA-(P+.020)

CUTTING LEFT HAND THREADSFIG. 34. Acme Screw Thread and Formulas.

Figure 33 shows the cutting of a left hand thread. The direc-tion of carriage feed is toward the tailstock. Gear set-ups andgeneral cutting procedure are exactly the same as for right handthreads with the changes in tool angles made necessary by the dif-ferent direction of carriage travel. Clearance angles and. side

The Acme screw thread (Fig. 34) is often found in powertransmissions, where heavy loads necessitate close-fitting threads.Another common application is in the lead screws and feed screwsof precision machine tools. The lead screw and cross feed screwof the Atlas lathe have Acme threads.

SECTION A-A

~ 3"TO 5"51DE CLEARANCE

A EIP~A

' 0 ' O " P P R O "IG. 36. Tool bit formed forcutting an external Acme thread.FI G. 83. Cut ting a left hand thread.

A - \ - - f - l j l ~ J c : I ~ A = = - -TO=P~'AC' "" mG"~- END

VIEW~ 29 'ANGLESIDErake should be the opposite of those shown in Figure 18. In cut-

ting left hand 600 type threads, the compound rest should be set at29 in the direction shown in Figure. 33 which is opposite thatfor right hand threads.

. 0 , - -SECTION A A

SIDECLEARANCE ANGLE \

FIG. 35Acme Thread Gauge ,

FIG. 37 (Le lt )Tool bit formed lor cut-tirig an internal Acmethread.


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Figures 36 and 37 show the proper tool forms for cuttingexternal and internal Acme threads. The forms must be checkedwith the Acme thread gauge (Fig. 35) during the cutting process.

The various steps in the cutting of an Acme thread are similarto those for 60 type threads (pages 13 to 19). Set the compoundrest at 0 and advance compound feed after cut, returning crossfeed each time to the same setting. Take lighter cuts than with600 type threads because the total cutting face of the tool islonger.

The square thread (Fig. 38) is rarely cut because it is a diffi-cult job and results in a thread which is not so strong as the Acme.Itis cut, however, for many vise and clamp screws and otherworm-screw forms. The Acme thread is recommended for all suchapplications-it is stronger, easier to cut, and capable of closer fits.

In the cutting of a square thread with a large lead, the toolangles must be absolutely correct. Clearance should be allowed ontwo sides, tapering from both the top and front of the tool (seeFigs. 39 and 41). Figure 40 explains how the important angle I I >must be determined.

CUTTING SQUARE THREADS

F"E D=.f.2 2FIG. 3S. Square Thread and Formulas.

External square threads should be cut to the minor diameterplus about .005 inch, internal square threads to the major diam-eter plus about .005 inch. The additional .005 inch allows a smallclearance at the bottom of the thread, which helps to compensatefor any small inaccuracies in the tool or cutting.

The tool must be fed directly into the work with the cross feed

THREAD CUTTING 25

(or compound rest feed), and care must be taken to avoid chatterand "hogging-in." The simplest method is to set the compoundrest at 0, feed in with the compound, and back out and return thetool with the cross feed. Take very light cuts when turning orboring a square thread.

t~ }TOPt

FRONT

FIG. 39. Tool bit for cutting external square threads.

c 1LEARANCE, ANGLEcIFIG. 40Determini ng the angle


14/32

26 MANUAL OF LATHE OPERATION THREAD CUTTI N G 2 7

CUTTING METRIC THREADS(Also Special Fractional Threads)

The Metric Standard screw thread form shown in Figure 45(page 28) is accepted almost universally wherever the metric. sys-tem is the standard of measurement. The metric thread angle andform is identical with that of the National Form thread, and thecutting operation is exactly the same, with one important excep-tion: the motor must be reversed after each cut. This procedureis necessary because metric threads have no definite relation tothe threading dial. *

WHITWORTH FORM THREADFigure 42 shows the Whitworth thread, a form which is stand-

ard in the British Isles for nearly all types of threads. The smallersizes of the Whitworth form are called British Standard Fine.

In order to cut theAmerican Standard Pipethread on the lathe withoutspecial dies or equipment,some variation in form is nec-essary. Excellent pipe-typethreads, satisfactory for com-mercial use and having thesame jamming effect whenforced into the nut or coup-ling, can be cut with a 60Vee type tool and a set-overof the tail stock to obtain ataper of approximately )/ ,iinch per foot. If the stockcannot' be mounted betweenlathe centers, the taper at-tachment (Part 8) is requiredfor the cutting operation.The threading operation issimilar to that for a standardVee thread and produces athread resembling the thread-ed portion shown in Figure44. Figure 45 shows a typeof pipe center recommendedfor supporting the stockwhile cutting pipe typethreads.

R~.1373P D o.64033PFIG. 42. Whitworth Thread and Formulas.

A Whitworth thread is cut in much the same manner as anAcme thread. There are two major differences: The thread angleis smaller, and the radius at the top and bottom of the thread mustbe shaped properly with a formed tool.

CUTTING PIPE-THREADSFigure 43 shows the exact form of the American Standard

Pipe thread when cut correctly in a pre-formed die. When turnedinto the receiving nut, the tapered lines cause the tight "jamming"for which the pipe thread is so well known. In a straight formthis thread is used in oil cups and several types of electrical fittings.

E L E NG TH O F T HD . W IT H P ER FE CTB O T T O M C U T O N T AP E R J4 ' P E R FT . 3 T H R E A D SON D I A .PERFECTTHREAD 2 THREADS F L A T TOP & BOTTOMTO P & BOTTOM P E R F E C T BOTTOM___ fL~LT.9E- -- - --- _-

A X I S

oI

FIG. 45. Pipe Centers.

FI G. 43. American Standard Pipe Thread and Formulas.*The six inch lathes are available with metric-pitch threads for cross

and compound feed screws and feed screw colters graduated in .02 mm.


15/32

i I

28 MANUAL OF LATHE OPERATION TH READ C urnNG 2 9USING THE THREADING D'IAL FOR MULTIPLE

THREADSAlthough only four marks are cut into the top of the threading

dial, there are actually eight different positions at which the half-nut lever can be engaged, Figure 48 shows the intermediate pointsbetween the four mainmarkings, These points can be marked withpencil, or the positions easily estimated. In the following para-graphs, "Lead in Threads Per Inch" is equal to 1 divided by Leadin Inches.CUTTING DOUBLE THREADSWITH LEAD IN THREADS PERINCH DIVISIBLE BY FOUR BUTNOT BY EIGHT (12, 20, 28, 36,

etc.) C AA single thread of this lead is

cut by engaging the half nuts atany of the four main markings onthe threading dial (0, A, B or Cin Figure 48). To cut the secondgroove of a double thread, thehalf nuts are engaged at any of

Example: To Cut a DoubleThread with a Pitch of 1/24 inchand a Lead of 1/12 inch. Set up the change gears for the lead inthreads per inch (12, not 24). Engage the half nut lever for thefirst cut when the stationary mark on the outside of the threadingdial is in line with anyone Q.fthe four main marks on the rotatingportion of the dial. Then return to the starting point and engagehalf nuts at anyone of the "b" positrons, taking the first cut on thesecond groove of the thread. The compound rest feed remains atone setting until both grooves have been cut to the same depth.

CUTTING DOUBLE AND QUADRUPLE THREADS WITH LEAD. IN THREADS PER INCH DIVISIBLE BY TWO, EUT NOT

BY FOUR (10, 14, 18, 22, etc.)A single thread of this lead can be cut only by engaging the

half nut lever at the "0" or "E" markings, on the threading dial.To cut the second groove of the double thread, the half nuts. areengaged at the "A" or He" markings, and the cutting operationis the same a s in the preceding paragraph.

D~.64952 x P pf="8FIG. 40. Metric Standard Screw Thread Form and Formulas.

The following cutting method applies to metric threads andalso to special fractional threads, wire feeds, and the threads inTable I, page 38, not. marked "Exact": After the half-nut leveron the carriage is engaged for the first cut, it should not be moveduntil the thread has been completed. As the tool reaches the endof each cut, back out the cross feed, stop the lathe, and reverse themotor until the tool has been returned to the starting position.Then advance the cross feed to its original 0 position, turn in thecompound" rest feed for the next cut, start the motor and repeatthe cutting operation. . " .. the "b" positions.~ - .MUL TIPLE THREADS

Multiple threads of almost any pitch and number ofstarts canbe cut by two methods. The threading dial is quick, simple andaccurate for some double threads and some quadruple or "multiple-four" threads. Multiple threads can also be cut by "slippingteeth" on either the spindle gear or the screw gear (see page 30).

Multiple threading requires larger tool clearance angles. Fig-ure 14 shows a double screw thread and Figure 47 shows a

FIG. 47th~~d~ dr Jt~~.e~~r.~four tim". the pitch.

quadruple or multiple four thread. These drawings illustrate howthe angle of advance has been increased-the tool clearance mustbe sufficient for the lead, not merely the pitch.

BF IG . 4 8Threading Dial Positions. The line andle tter for the "O" position is ma rked in theface' of the dial. Lines for HA:' "B, 'J and"C" positions are marked, but not the let-te rs themselves. The four "b" positionsmay 'be marked by t he ope rator a s needed.


16/32

30 T HR EAD C UT TIN G 31A N U A L O F LA T H E O P E R A T IO N

For quadruple threads of this lead, engage the half nut lever atthe "0" or "B" markings for the first groove, at the b Ior b:J posi-tions for the second groove, at the H A " or "C" markings for thethird groove, and at the b2 or b4 positions for the fourth groove. Thesetting of the compound rest feed is changed only after each of thefour grooves has been cut to the same depth.

To Cut Double Tht-eads: ._. ;. ..Sl ip 16 teeth to cut the second groove.To Cut Quadruple Threads:__":_Slip 8 teeth to cut the second

groove, 8 teeth more to cut the thirdgroove, and 8 teeth more to cut thefourth groove.

Each thread groove is cut to its complete depthand finishe d before starting the next groove.CUTTING DOUBLE AND QUADRUPLE THREADS WITH LEAD

IN THREADS PER INCH DIVISIBLE BY ONE, BUT NOTBY TWO (ODD NUMBERS) GEAR TRAINS FOR CARRIAGE FEEDS

A single thread of this lead is cut by engaging the half nutlever at the "0" marking. To cut the second groove of the doublethread, the half nuts are engaged at the HB" marking on thethreading dial. The cutting operation is the same as in thepreceding paragraph.

For quadruple threads of this lead, engage the half nut leverat the "0" marking for the first groove, at "A" for the secondgroove, at HE" for the third groove, and at "C" for the fourthgroove. The setting of the compound rest feed is changed onlyafter each of the four grooves has been cut to the same depth.

The automatic longitudinal carriage feed per spindle revolutionis obtained by setting up the gear train in the same manner as forthread cutting (pages 3 to 11). The feed in inches is equal to

1 For example, a feed of .0078 inch requires thethreads per inchgear set-up as 128 threads per inch.The four most common carriage feeds, as shown in the thread-ing chart (page 5), are .0078, .0048, .0039, and .0024 inch per spindle

revolution. Refer to the threading chart and the four followingparagraphs when changing these gear set-ups. Table II on page 40includes gear set-ups for other carriage feeds.CUTTING MULTIPLE THREADS BY SLIPPING

TEETH ON THE COMPOUND GEARDouble and quadruple threads can also be cut by "slipping

teeth" on the compound gear. This practice is not so common asthe use of the threading dial, but is not complicated.

To cut multiple threads by slipping teeth on the compound gear:cut the complete first groove to a minor diameter dependent uponpitch of the desired thread. The change gear train should be ar-ranged for the desired lead. Its important to use the same 0 pointof reference to cut each thread-be sure to remember this pointduring the cutting operations.Refer to the table on page 31, then slip the required number of

teeth by marking adjacent teeth on the compound gear and the gearmeshing with the compound gear. Drop the entire gear bracketlow enough to disengage the gears and turn the compound gearforward the proper number of teeth by rotating spindle by hand.Raise the gear bracket so that the previously marked gear toothmeshes with the newly selected compound gear tooth.

~,TUMBLERGEARS

GEAR

FIG. 49. Gear set-up for .00'18 inch carriage Feed ( see page 32).


17/32


GEAR TRAIN FOR .0078 INCH CARRIAGE FEED(See Fig. 49, page 31)

L Place 64 tooth gear in back position on screw stub.2. Place 32 tooth gear and 64 tooth gear on sleeve in Position

C, with 32 tooth gear in back position. Tighten so that 32 toothgear meshes with 64 tooth gear on screw stub.

3. Place 48 tooth gear and 24 tooth gear on sleeve in PositionA, with 48 tooth gear in back position .. Tighten so that 24 toothgear meshes with 64 tooth gear in Position C.

4. Swing entire gear bracket upward and tighten so that 48tooth gear in Position A meshes with 32 tooth compound tumblergear.

GEAR TRAIN FOR .0048 INCH CARRIAGE FEED

TOOTH GEARGEAR

24

20 TOOTHGEAR

FIG. 50. Gear set-up for .0048 inch carriage feed.1. Place 64 tooth gear in back position on screw stub.2. Place 20 tooth gear and 64 tooth gear on sleeve in Position

C, with 20 tooth gear in back position. Tighten so that 20 toothgear meshes with 64 tooth gear on screw stub. .

3. Place 48 tooth gear and 24 tooth gear on sleeve in PositionA, with 48 tooth gear in back position. Tighten so that 24 toothgear meshes with 64 tooth gear in Position C.

4. Swing entire gear bracket upward and tighten so that 48.tooth gear in position A meshes with 32 tooth compound tumblergear.

TH READ CUTTI NG 33

GEAR64 TOOTH

GEAR

24

64 TOOTH GEAR32 TOOTHGEAR

FIG. iiI. Gear se t- up for .0039 inch ca rriage feed .

GEAR TRAIN FOR .0039 INCH CARRIAGE FEED1. Place 64 tooth gear i11 front position on screw stub.2. Place 64 tooth gear and 32 tooth gear on sleeve in Position

C, with 64 tooth gear in back position. Tighten so that 32 tooth gearmeshes with 64 tooth gear on screw stub.

3. Place 24 tooth gear and 48 tooth gear from screw stub onsleeve in Position A, with 24 tooth gear in back position. Tightenso that 24 tooth gear meshes with 64 tooth gear in Position C.4. Swing entire gear bracket upward and tighten so that 48

tooth gear in Position A meshes with 16 tooth compound tumblergear.


18/32

MANUAL OF LATHE OPERATION

GEAR TRAIN FOR .0024 INCH CARRIAGE FEED

III

20 TOOTH GEAR GEAR

FIG. 52. Gear set-u p for .0024 inch carria ge fe ed.

1. Place 64 tooth gear in front position on screw stub.2. Place 64 tooth gear and 20 tooth gear on sleeve in Position

C, with 64 tooth gear in back position. Tighten so that 20 toothgear meshes with 64 tooth gear on screw stub.

3. Place 24 tooth gear and 48 tooth gear on sleeve in PositionA, with 24 tooth gear in back position. Tighten so that 24 toothgear meshes with 64 tooth gear in Position C.

4. Swing entire gear bracket upward and tighte~ so that 48tooth gear in Position A meshes with 16 tooth compound tumblergear.

THREAD CUTTING 3 5

SPECIAL THREADS AND FEEDSEngineers have charted over a thousand threads and feeds be-

tween the coarsest thread and the finest feed. Tables I and II inthe following section give proper gear set-ups for a wide varietyof special threads and feeds. Most of these set-ups are exact-some are accurate to the limits mentioned. Table III gives set-upsfor metric threads with pitch between 0.5 and 3.0 millimeters.

ELECTRICAL COIL WINDINGFigure 54 shows a coil

winding operation with asimple guide mounted inplace of the tool post onthe compound rest. Thisset-up is very popular withelectrical shops and hasdone much to make coilwinding on the lathe a sim-ple job. This guide is avail-able at the factory.Feeds are available to

match the diameter of B &S magnet wire in sizes be-tween 12 and 40, using bare FJG. 64. Winding- a coil.wire or any of the following insulations: single cotton, doublecotton, single silk, double silk, enamel, silk enamel, and cottonenamel. Gear set-ups are given in the following tables.

Feeds are also available for spring making, wire wrapping andcoil winding with steel and iron wire in the following gauges:American Steel and Wire Company, music wire, American or B& S, and Washburn and Moen. Gear data for winding iron andsteel wire and wires with other than enamel insulation are given inthe following section.

/


19/32

TABLES FOR THREAD CUTTING

37

I. . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . ODDPITCH THREADSII CARRIAGE FEEDSIII METRIC THREADSIV DEPTH AND DOUBLE DEPTH OF

NATIONAL FORM THREADSV NATIONAL COARSE THREAD DIMENSIONSVI NATIONAL FINE THREAD DIMENSIONSVII. FRACTIONAL SIZE THREAD DIMENSIONSVIII MACHINE SCREW THREAD DIMENSIONSIX WHITWORTH THREAD DIMENSIONSX BRITISH ASSOCIATION THREAD Dlli-rENSIONSXI. INTERNATIONAL STANDARD THREAD

DIMENSIONS-METRICXII FRENCH STANDARD THREAD DIMENSIONSXIII. ACME STANDARD THREAD DIMENSIONSXIV SQUARE THREAD DIMENSIONSXV STRAIGHT PIPE THREAD DIMENSIONSXVI. STOVE BOLT THREAD DIMENSIONSXVII toXXVI GEAR SET-UPS FOR COIL WINDING


20/32

38 3 9H READ C UTTI NGANUAL OF LATHE OPERATION

TABLE I-GEAR SET-UPS FOR THREADS FROM 7%THROUGH 79PER INCH NOT SHOWN ON

THE THREADING CHART

Table I-Continued

Threads Accuracy Gear 011 Position C Position B Position A Position D Comp oundper inch per inch Screw B F B F B F B F TG,::~~er Note

The threading dial can be used when cutting threads below marked "exact"in the column under "Accuracy." All other threads must be cut in thesame manner as. metric threads (See Page 28). Set-ups which cal1 for"Position D" require a special extension bracket assembly available fromthe factory. Extra gears are also available from the factory at nominal cost.

h/400Exact1/3000Exact

54B 3 6 5652F54B 40 6454F

32163 216

51525354

56 46xxS 64154 44xxS 641

j

1/70001/3201/5801 / 770

64B 44 64 S2 4456B 2 4 44 40 3654B 32 54 56 4440B 641 xxS 2 0 48

32323232

5S575859

Threads Accuracy Gear on Position C Position B Position A Position D Compoundper inch per inch Screw B F B F B F B F TG~~~er Note

64 52Exact1/4701/950Exact

40F 24 6420F 46 5452B 56 2456B 48 3 6

641 xxS641 xxSxxS 521 46 54

2 0 40 441 xxS

7 . 58 . 59.5

1 0 . 5

323232 p ('')32 *

xxS 641xxS 56154 4652 44

1616323 2

Exact1/15001 / 62 01/2100

48B 3 2 4054B 46 5248B 20 4464B 24 40

6061626 3

641 xxS461 xxS46I xxS521 xxS

1 2 . 51 3 . 5151 7

ExactExactExact1/560

40F54F54B 3 6 4040F

32323 232

2 0 3 220 402 0 4046 54

40 2 4xxS 641521 xxS 32 5644 52 xxS 481

659 .6676 8

Exact1/751 / 6701 / 6 8 0

48B 32 5244B 36 5440F 44 4640F 46 3 2

3 2161616

d' " (")(")xxS 64I

481 xxS 32 56xxS 641

xxS 44I 54 32

(*)4 2 0 xxS 561641 xxS641 xxS56 54

ExactExact1/7101/7301/740Exact1/1900Exact

54B40B64B48B

36 46/630ExactExact1/780

16323232

161 6 .1632

48F 40 4656F 36 4840F40B 40 56

6 9707 17 3

192 12529

ddh

36 4020 36

40 32

56 40 xxS 641xs S 44I32 36 xxS 481xxS 541

16 ('")16 d16 (~)p16

54F40F52F44B

46 2436 245 2 4032 56

747 57 677

54! xxS46 32 xxS 54!44 4052 44

Exact1/6200Exact1/340

48F48F40B40B

40 3 203 13 33 4

32163232

3 2 40*)d

52 563 2 4832 46

xxS 6413 2 36 xxS 441

Exact1/790

54B 36 5254 F 52 40 16167 87 940F xxS 54I54B 2 4 4652B 40 5254F 52 36

56 3 240 56 52! xxS36 3 256I xxS

35373 839

Exact1/3601/1580Exact

3232323 2

(*)p

SYMBOLS:/410Exact1/2100Exact

56 44541 xxS

xxS 401 3 2 2054 2 4

h1424345

46B48F44B40F

40 5656 3236 44xxS 521

3 23 23 232

d-extra 40 tooth gearh-extra 56 tooth gearj-extra 54 tooth gear

F-position away from headstockB-position toward headstockI-idler gear

t*

xxS 641xxS 52154I xxSxxS 641

Exact1/470ExactExact

46F54B56F40B

16163216

46474950

p-extra 52 tooth gear xxS-steel spacert-extra 44 tooth gear ':'-extra sleeve, bushing and bolt assembly

C*)-special extension bracket assembly46 4056 32 !J

d2 40


21/32


TABLE II-GEAR SET-UPS FOR CARRIAGE FEEDSEight diflere.nt carriage feeds between .001046 a.nd .0080 inch per spindlerevolution are available 0.0 the new six-inch lathes in addition to the fourmost common feeds pictured and described in detail between pages 31 and34. Two of these set-ups call for an extra position (Position D) whichrequires a special extension bracket assembly available from the factory.When the material or job requires a certain carriage feed, refer to the tablebelow. Feeds for electrical coil winding begin with Table xvn.Feed Thread.Inches per inch

Gear on Position C Position B Position A Position D C12:~~~~doteScrew B F B F B F B F Gear

.008 124.8 64B 20 52 54 36 32

.00 7 143.94 64B 20 54 40 24 3 2

.00 6 16 6.4 64B 20 52 xxS 561 1 6

.0 05 199.1 64F 64 3 2 36 56 16

.004 249.6 64F 52 2 0 2 4 36 xxS 481 16 (")

.0039 25 6 64F 64 32 2 4 48 1 6

.0 021 478 64F 64 2 0 24 56 16

. 00 10 46 956 64B 20 64 56 24 24 48 16 fe)

SYMBOLS:i-extra 24 tooth gear F-position away from headstock(*)-special extension bracket assembly B-position toward headstockxxS-steel spacer I-idler gear

S-Spacer gear

THREAD CUTTING 4 1

TABLE III-GEAR SET-UPS FOR METRIC THREADSTwo of the standard change gears furnished with the new six-

inch lathe, the 52 tooth gear and 44 tooth gear, combine to give arat io of 44/52 or .846154, which is an almost exact function of 2..54,the English to Metric ratio, Thus, it is possible to cut metricthreads very close to the standard metric pitches.

Refer to page 28 when cutting metric threads. The threeset-ups below which call for "Position D" require a specialextension bracket assembly available from the factory.

Pitch Gear on Position C Position B Position A Posit ion D CompoundMM. Screw B F B F B F B F Tumbler NoteGear

.5 48B 541 xxS 24 56 40 44 32 (*)

.6 56B 36 64 44 52 32

.7 64B 2 4 32 44 52 32

.7 5 54B 32 40 44 52 32

. 8 54B 46 64 44 52 32

.9 46B 36 52 44 52 321. 0 40E 32 48 44 52 321.25 4A-F 48 52 401 2 0S 32

1.50 44F 40S 52I 461 20 5 321.75 HE 56 40 20 S 461 48 52 32 ("')2. 0 40E 48 44 36 52 641 2 0S 32 (*)2. 5 44F 24 52 641 20 S 323. 0 44F 2 0 52 641 20 S 32


22/32

42 MANUAL O F LATHE OPERATION THREAD CUTTING 43

TABLE IV TABLE VDEPTH AND DOUBLE DEPTH OF NATIONAL FORM THREADS NATIONAL COARSE THREAD SERIES

This table shows Depth and Double Depth for National Form (Formerly U. S. Standard)Threads cut with a formed tool, and also when cut with a Vee THREAD DIMENSIONS AND TAP DRILL SIZEStype tool. The two columns at the extreme right give the properdepth of compound feed to obtain the correct thread depth with Nominal Threads Major Minor Fitch Tap Dri ll Clearancethe compound rest set at an angle of 29". Size per Inch Diamete r Diameter Diameter for 75% DrillInches Inches Inches Thread Size"

Nat ional Form Tool Vee Form Tool Depth of Feed 64 .0730 .0527 .0629Thread. Pitch Single Double Single Double Single Depth 53 472 56 .0860per Inch Inches Depth of Depth of Depth 01 Depth 01 N. F. Tool Vee Form .0628 .0744 50 42Thread Thread Thread Thread Tool 3 48 .0990 .0719 .0855 47 364 40 .1120 .0795 .0958 43 31

4 .2500 .1624 .3248 .1894 .3789 .186 .2164% .2222 .1443 .2887 .1684 .3368 .165 .193 5(%) 40 .1250 .0925 .1088 38 295 .2000 .1299 .2598 .1516 .3031 .148 .173 6 32 .1380 .0974 .1177 36 255% .1818 .1181 .2362 .1378 .2755 .135 .157 8 32 .1640 .1234 .1437 29 166 .1667 .1083 .2165 .1263 .2525 .124 .144 10 24 .1900 .1359 .1629 25 13/64"7 .1429 .0928 .1856 .1082 .2165 .106 .1238 .1250 .0812 .1624 ,0947 .1894 .093 .108 12 24 .2150 .1619 .1889 16 7/32"9 .1111 .0722 .1443 .0842 .1684 .083 .095 1/4# 20 .2500 .1850 .2175 7 17/64/110 .1000 .0650 .1299 .0758 .1515 .074 .087 5/16" 18 .3125 .2403 .2764 F 21/64#11 .0909 .0590 .1181 .0689 .1377 .067 .078 3/8# 16 .3750 .2938 .3344 5/16# 25;164"12 .0833 .0541 .1083 .0631 .1263 .062 .07213 .0769 .0500 .0999 .0583 .1166 .057 .06,7 7/16# 14 .4375 .3447 .3911 U 29/64/114 .0714 .0464 .0928 .0541 .1082 .053 .062 1/2" 13 .5000 .4001 .4500 27/64" 33/64"16 .0625 .0406 .0812 .0473 .0947 .046 .054 9/16" 12 .5625 .4542 .5084 31/64" 37/64 118 .0556 .0361 .0722 .0421 .0842 .041 .047 5/8# 11 :6250 .5069 .5660 17/32/ f 41/64"

: 20 .0500 .0325 .0650 .0379 .0758 .037 .043I 3/4" 10 .7500 .6201 .6850 21/32" 49/64/122 .0454 .0295 .0590 .0345 .0690 .034 .03824 .0417 .0271 .0541 .0316 .0632 .031 .036 7/8" 9 .8750 .7301 .8028 49/64" 57/64"27 .0370 .0241 .0481 .0281 .0562 .028 .032 1" 8 1.0000 .8376 .9188 7/8" 1- 1/64"28 .0357 .0232 .0464 .0270 .0541 .027 .031 1Ya" 7 1.1250 .9394 1.0322 63/64" 1- 9/64"30 .0333 .0217 .0433 .0253 .0506 .025 .029 1%" 7 1.2500 1.0544 1.1572 1- 7/64" 1-17/64"32 .0313 .0203 .0406 .0237 .0474 .023 .02736 .0278 .0180 .0361 .0211 .0421 .021 .024 1%# 6 1.3750 1.1585 1.2667 1- 7/32" 1-25/64"40 .0250 .0162 .0325 .0189 .0379 .019 .021 1%# 5 1.5000 1.2835 1.3917 1-11/32# 1-33/64"44 .0227 .0148 .0295 .0172 .0345 .017 .020 1%'i 5 1.7500 1.4902 1.6201 1- 9/16" 1-49/64"48 .0208 .0135 .0271 .0157 .0315 .015 .018 2" 4% 2.0000 1.7113 1.8557 1-25/32# 2- 1/32"50 .0200 .0130 .0260 .0151 .0303 .015 .01756 .0179 .0116 .0232 .0135 .0271 .013 .016 2%" 4% 2.2500 1.9613 2.1057 2- 1/32" 2- 9/32/12%" 4 2.5000 2.1752 2.3376 2%,' 2-17/32"64 .0156 .0101 .0203 .0118 .0237 .012 .014 2%# 4 2.7500 2.4252 2.5876 2%# 2-25/32"72 .0139 .0090 .0180 .0105 .0210 ; .010 .01280 .0125 .0081 .0162 .00945 .0189 .009 .011 3" 496 .0104 .0068 .0136 .00901 .01802 .008 .010 3.0000 2.6752 2.8376 2%" 3- 1/32"3%" 4 3.2500 2.9252 3.0876 3" 3- 9/;l2"

3%" 4 3.5000 3.1752 3.3376 3Y4" 3-17/32"Note: Using Formed Tool-Minor Diameter = Major Diameter mInus 30/4" 4 3.7500 3.4252 3.5876 3?/,_" 3-25/32"Double Depth of Thread in National Form Tool column. 4" 4 4.0000 3.6752 3.8376 3% " 4- 1/32"

rUsing Vee Tool-Minor Diameter = Major Diameter minusDouble Depth of Thread in Vee Form Tool column. "Clearance drill makes hol e with st 'atl dard clea rance for diamet er o f nominal s ize. Il ------- ~ .-


23/32

44 M A N U A L O F L AT H ~ O PE RA TIO N T H R EA D C UT T IN G 45TABLE VI TABLE VII

NATIONAL FINE THREAD SERIES FRACTIONAL SIZES(Formerly S. A. E.) NATIONAL SPECIAL THREAD SERIES

THREAD DIMENSIONS AND TAP DRILL SIZES THREAD DIMENSIONS AND TAP DRILL SIZESNominal Thread. Major Minor Pitch Tap Drill ClearanceSi per Inch D,iameter Diameter Diameter for 75% arill

Nominal Thlead. Major Minor Pitch Tap Drill Clearance Inches Inches Inches Thread Slze*Size per Inch Diameter Diameter

Diameter for 750/. Drill 1/16/1Inches Inches Inches Thread Si2e* 64 .0625 .0422 .0524 3/64" 515/64" 60 .0781 .0563 .0673 1/16" 453/32" 48 .0938 .0667 .0803 49 400 80 .0600 .0438 .0519 3/64" 51 7/64" 48 .1094 .0823 .0959 43 3272 .0730 .0550 .0640 53 47 1/8" 32 .1250 .0844 .1047 3/32/1 299/64" 40 .1406 .1081 .1244 32 242 64 .0860 .0657 .0759 50 42 5/32" 32 .1563 .1157 .1360 1/8" 19

.0874 45 36 5/32" 36 .1563 .1202 .1382 30 193 56 .0990 .0758 11/64/1 32 .1719 .1313 .1516 9/64" 143/16" . 24 .1875 .1334 .1604 26 84 48 .1120 .0849 .0985 42 31 3/16" 32 .1875 .1469 .1672 22 813/64" 24 .2031 .1490 .1760 20 350.-8,) 44 .1250 .0955 .1102 37 29 7/32" 24 .2188 .1646 .1917 16 16 ,40 .1380 .1055 .1218 33 25 7/32" 32 .2188 .1782 .1985 12 115/64" 24 .2344 .1806 .2073 10 1/4"8 36 .1640 .1279 .1460 29 16 1/4" 24 .2500 .1959 .2229 4 17/64"

1/4" 27 .2500 .2019 .2260 3 17/64"10 32 .1900 .1494 .1697 21 13/64" 1/4" 32 .2500 .2094 .2297 7/32" 17/64"5/16" 20 .3125 .2476 .2800 17/64" 21/64"12 28 .2160 .1696 .1928 14 7/32" 5/16" 27 .3125 .2644 .2884 J 21/64"1/4" 28 .2500 .2036 .2268 3 17/64" 5/16" ~2 .3125 .2719 .2922 9/32" 21/64"3/8" 20 .3750 .3100 .3425 21/64" 25/64"5/16" 24 .3125 .2584 .2854 I 21/64/1 3/8" 27 .3750 .3269 .3509 R 25/64"7/16" 24 .4375 .3834 .4104 X 29/64"3/8" 24 .3750 .3209 .3479 Q 25/64" 7/16" 27 .4375 .3894 .4134 Y 29/64"1/2" 12 ..5000 .3918 .4459 27/64" 33(64"7/16" 20 .4375 .3726 .4050 25/64" 29/64" 1/2" 24 .5000 .4459 .4729 29/64" 33/64"1/2" 27 .5000 .4519 .4759 15/32" 33/64"1/2" 20 .5000 .4351 .4675 29/64" 33/64" 9/16" 27 .5625 .5144 .5384 17/32" 37/64"9/16" 18 .5625 .4903 .5264 33/64" 37/64" 5/8" 12 .6250 .5168 .5709 35/64" 41/64"5/8" 27 .6250 .5769 .6009 19/32" 41/64"11/16" 11 .6875 .5694 .6285 19/32" 45/64"5/8" 18 .6250 .5528 .5889 37/64" 41/64" 11/16" 16 .6875 .6063 .6469 5/8" 45/64"3/4" 12 .7500 .6418 .6959 43/64" 49/54"3/4" 16 .7500 .6688 .7094 11/16# 49/64" 3/4" 27 .7500 .7019 .7259 23/32" 49/64"

14 .8750 .8286 13/16" 57/64" 13/16" 10 .8125 .6826 .7476 23/32" 53/64"7/8" .7822 7/8" 12 .8750 .7668 .8209 51/64" 57/64"1" 14 1.0000 .9072 .9536 15/16" 1- 1/64" 7/8" 18** .8750 .8028 .8389 53/64" 57/64"7/8" 27 .8750 .8269 .8509 27/32" 57/64"15/16" 9 .9375 .7932 .8654 53/64" 61/64"1%" 12 1.1250 1.0168 1.0709 1 - 3 /6 4/ 1 1- 9/64" 1" 12 1.0000 .8918 .9459 59/64/1 1- 1/64"1~" 12 1.2500 1.1418 1.1959 1-11/64" 1-17/64" 1" 27 1.0000 .9519 .9759 31/32" 1- 1/64"1%". 5% 1.6250 1.3888 1.5069 1-29/64" 1-41/64"1%" 12 1.3750 f,2668 1.3209 1-19/64" 1-25/64" I V a " 5 1.8750 1.6152 1.7451 1-11/16" 1-5'7/64"2W' 4% 2.1250 1.8363 1.9807 1-29/32" 2- 5/32"1%" 12 1.5000 1.3918 1.4459 1-27/64" 1-33/64" 2%" 4 2.3750 2.0502 2.2126 2- 1/8 " 2-13/32"

* * Sta.ndard Spark Plug Size*Clearance drill makes hole with standard clearance for diameter of nominal size. 'Clearance drill makes hole with standard clearance for diameter of nominal size. il


24/32


TABLE VIIIMACHINE SCREW SIZES

THREAD DIMENSIONS AND TAP DRILL SIZES-NATIONAL SPECIAL THREAD SERIES

Nominal Threads Major Minor Pitch Tap Drill ClearanceDiameter Diameter Diameter for 75% DrillSiz e per Inch Inches, Inches Inches Thread Siae"-------

1 56 .0730 .0498 .0614 54 474 32 .1120 .0714 .0917 45 314 36 .1120 .0759 .0940 44 31

5(Vs) 36 .1250 .0889 .1070 40 296 36 .1380 .1019 .1200 34 257 30 .1510 .1077 .1294 31 217 36 .1510 .1149 .1330 Y I" 218 30 .1640 .1207 .1423 30 168 40 .1640 .1315 .1'178 28 169 24 .1770 .1229 .1499 29 139 30 .1770 .1337 .1553 27 139 32 .1770 .1364 .1567 26 1310 28 .1900 .1436 .1668 23 13/64"10 30 .1900 .1467 .1684 22 13/64"12 32 .2160 .1754 .1957 13 7/32"14 20 .2420 .1770 .2095 10 17/64"14 24 .2420 .1879 .2149 7 17/64"

"Cl ear -ance dr il l rnakes hol e wit h s tandard c learance for d iame ter o f nominal si ze .

THREAD CUTTI NG 47

TABLE IXB.RITISH STANDARD -WHITWORTH FORMTHREAD DIMENSIONS AND TAP DRILL SIZES

Nominal Threads Major Minor Pitch Tap Drill ClearanceSize per Inch Diameter Diameter Dfameter for Full DrillInches Inches Inches Tbr~ad Size*1/16" 60 .0625 .0412 .0518 57 513/32" 48 .0938 .0671 .0804 50 401/8" 40 .1250 .0930 .1090 40 295/32" 32 .1563 .1162 .1362 31 193/16" 24 .1875 .1341 .1608 28 87/32" 24 .2188 .1654 .1921 17 11/4" 20 .2500 .1860 .2180 9 17/64"9/32" 26 .2813 .2321 .2566 C 19/64"5/16" 18 .3125 .2414 .2769 1/4" 21/64"3/8" 16 .3750 .2950 .3350 5/16" 25/64"7/16" 14 .4375 .3460 .3918 T 29/64"1/2" 12 .5000 .3933 .4466 Z 33/64"9/16" 12 .5625 .4558 .5091 15/32" 37/64"5 / 8 " 11 .6250 .5086 .5668 17/32" 41/64"11/16" 11 .6875 .5711 .6293 19/32" 45/64"3/4" ! O .7500 .6219 .6860 4 1 / 6 4 " 49/64"13/16" 10 .8125 .6844 .7485 45/64/1 53/64"7/8" 9 .8750 .7327 .8039 3/4" 57/64"1" 8 1.0000 .8399 .9200 55/64" 1- 1/64"1%" 7 1.1250 .9420 1.0335 31/32" 1- 9/64"17'


25/32

M A N U A L 0 F L A T H E O P E R A T IO N4 8 T HR EA D C UTT IN G 4 9

TABLE XIINTERNATIONAL STANDARD - METRICTHREAD DIMENSIONS AND TAP DRILL SIZES

TABLE XIIFRENCH STANDARD THREADS - METRICTHREAD DIMENSIONS AND TAP DRILL SIZES

Tap Drillfor 75%ThreadNo. or Inches

Tap Drillfor 75%Threadmlm

ClearanceDrillSize'l'Tap Drillfor 75%Threadmlm

Tap Drillfor 75%ThreadNo. Of I nches

PitchDiameterm/mMinorDiametermlm

MajorDiameterm/m

ClearanceDrillSize"

Pitchm/m

MajorDiameterm/m

MinorDiameterm/m

PitchDiameterm/m

Pitchm/m

1 . S2.02.S3.03.54.04.55.05.56.07.08.09.010.012.014.016.018.020.0?2,Q24.026.028.030.032.034.036.038.040.042.044.046.0

,35.45.45.60.60.75.75.90.901.001.001.001.001.501.502.002.002.502.502.503,003.003.003.503.503.504.004.004.004.504.504.505.005.00

1/16484540

41363 129

1.051.421.922.222.723.033.533.834.334.705.706.707.708.0510.0511.4013.4014.7516.7518.7520.1022.1024.1025.4527.4529.4S30.8032.8034.8036.1S38.1540.1541.5043.50

1.2731.7082.2082.6103.1103.5134.0134.4154.9155.3506 . 3 S 07.3508.3509.02611.02612.70114.7011 6 . 3 7 618.37620.37622.05124.05126.05127.72729.72731.72733.40235.4023 7 . 4 0 239.07741.07743.07744.75246.752

1.11.52.02.42.93.253.754 . 14.65.06.07.08.08.610.512.014.015.517.519.521.023.025.026.528.530.532.034.036.037.039.041.043.045.0

5753473/32"

4 84 13229

1.61.92.12.5

1.7402.0402.3082.675

1.481.782 ,022.35

2.02.32,63.0

.40

.40

.45

.5033302620149

I S / 6 4 "I

2316103

15/64"1 / 4 "

1 9 / 6 4 "11/32"

2316103

33302619

2.93 . 33.754.2

3.1103.5454 . 0 1 34.480

2.723.093.533.96

3.54.04.55.0

.60

.70

.75.80

15/64"1/4"

19/64"11/32"

149

15/64"H

4.65.06.06.8

4 . 9 1 55.3506.3507.188

4.334 . 7 05.706 . 3 8

5.56.07.0s .o

.901.001.001.25

5/16"RZ

1S/32"35/64"39/64"11/16"4 9 / 6 4 "53/64"57/64"63/64"

1- 3/64"1- 1/8 "1-13/64"1-17/64"1-21/64"1~27/64"1-29/64"1-17/32/11-39/64"1-11/16"1-49/64"

3 / 8 "2 7 / 6 4 "1/2"9 / 1 6 "

3 / 8 "27/64"29/64"1/2"

5/16"RVZ

7.88.69 . 610.5

8.1889.02510.02610.863

7.388.059.059.73

1.251.501.501.75

9.010.011.012.0 21/32"

4 7 / 6 4 "1 3 / 1 6 "57/64"31/32"

1 - 3 /6 4"1- 3/64"1 - 1 3 / 5 4 #

9/16"9/16"21/32"4 7 / 6 4 "

3 3 / 6 4 "15/32"35/64"41/64"3 9 / 6 4 / 111/16/14 9 / 6 4 / 153/64"

13.012.014.016.5

13.18812.70114.7011 7 . 0 2 6

12.3811.4013.4016.05

1.252.002.001.50

14.0*14.016.018.0*

47/64"13/16"5 7 / 6 4 "31/32"1- 3/32"1-13/64"1-21/64"1- 7/16"1 - 9 /1 6' !1 - 4 3 / 6 4 "1-13/16"1-29/32"

15.517.519.521.0

16.37618.37620.37522.051

14.7516.7518.7520.10

2.502.502.503.00

18.020.022.024.0 1 - 9 /3 2"

1-23/64"1- 7/16"1-33/64/1

l S / 1 6 "1- 3 / 6 4 "1-11/64"1 - t 7 / 6 4 "

24.02 6 . 529.532.0

25.05127.72730.72733.402

23.1025.4528.4530.80

27.030.033.036.0

3.003.503.504.00 1 - 1 9 / 3 2 / 1

1-43/64"1 - 3 / 4 "

1 - 5 3 / 6 4 "1-13/16"

2"

1 - 3 / 8 "1-29/64"1-37/64"1-11/16"

35.037.040.043.0

36.40239.07742.07744.752

3 3 . 8 036.1539.1541.50

4.04.504.505.00

39.042.045.048.0 4 8 . 0

50.0* Special Spark Plug Sizes[C 'lear ance dril l makes ho le wi th s tandard cl ea rance for diameter. of nominal size. "Clearance drill makes hole with standard clearance for diameter of nominal size.


26/32

50 MANUAL Or: LATHE OPERATION

TABLE XIIIACME STANDARD THREAD DIMENSIONS

Threadsper Inch

PitchInchesPDepthofThread

DoubleDepth o jThreadWidth ofTop ofThread

Width ofSpace atBottom ofThread11%2345678910

13/41/21/31/41/51/61/71/81/91/10

.5100.3850.2600.1767

.1350.1100.0933.0814

.0725.0655.0600

1.0200.7700.5200.3534.2700.2200.1867.1628.1450.1311.1200

.3707.2780.1853.1235.0927.0741.0618.0530.0463.0413..0371

.3655.2728.1801.1183

.0875.0689.0566.0478

.0411.0361.0319Note: Minor Diameter equals MajorDiameter minus Double Depth of Thread.

TABLE XIVSQUARE THREAD DIMENSIONS

Thread.per Inch

Width ofSpace atBottomof ThreadPitchInchesP

Depth ofThread

DoubleDepth ofThreadWidth ofTop ofThread

22%33%44%55%67891011121314151618202224

1.0000.7500.6667.5714.5000.4000..3333.2857.2500.2222.2000.1818.1667.1429.1250.1111.1000.0909.0833.0769.0714.0667.0625.0556.0500.0455.0417

.5000.3750.3333.2857.2500.2000.1667.1429.1250.1111.1000.0909.0833.0714.0625.0556.0500.D45S.'0417.0385.0351.0333.0312.0278.0250.0227.0206

1.0000.7500.6667.5714.5000.4000.3333.2851.2S00.2222.2000.1818.1667.1429.1250.1111.1000.0909.0833.0769.0714.0667.0625.0556.0500.0455.0417

.5000.3750.3333.2857.2500.2000.1667.1429.1250.1111.1000.0909.0833.0714.0625.0556.0500.0455.0417.0385.0357.0333.0312.0278.0250.0227.0208-

.5000.3750.3333.2857

.2500.2000.1667.1429

.12S0.1111.1000.0909

.0833.0714.0625.OS56.0500.0455.0417.0385.0357.0333.0312.0278.0250.0227.0208================================

THREAD CUTTING 51

TABLE XVSTRAIGHT PIPE THREADS

AMERICAN STANDARD FORMTHREAD DIMENSIONS AND TAP DRILL SIZES

Nomina]PipeSizePitchDiameterInches

Tap Drillfor FunThreadThreadsper Inch

MajorDiameterInchesMinarDiameterInches

Y a "%!!"%"%"~"

I "1y.;"1~"2"2%"3"3%"4"

271818141411 %11 %l l Y < i11% .8888

.4044

.5343

.6714

.83561.04601.30821.65301.89192.36582.86223,48853.98884,4B71

.3451

.4455

.5826

.7213-.93181.16901.51381.75272.22672.66223.28853.78884.2871

.3748

.4B99

.6270

.7784

.98891.23861.58341.82232.29632.76223.38853.88884.3871

11/32"7/16"37/64"23/32"59/64"

1.. 5/32"1- 1/2 "1-47/64"2- 7/32"2- 5/8 "3- 1/4 "3- 3/4 "4- 1/4 "

Threadsper Inch

MajorDiameterInches

322824221818161413

.1250.1630.1950.2220.2500.3125.3750.4375.5000

MinorDiameterInches

.0910.1250.1510.1740.1980.2403.2938.3447.4000

TABLE XVISTOVE BOLTS

MANUFACTURERS STANDARD FORM-60 THREADTHREAD DIMENSIONS AND TAP DRILL SIZES

NominalSize

TapDrill

PitchDiameterInchesClearanceDrillSiae"

1/8"5/32"3/16"7/32"1/4"5/16"3/8"7/16/11/2"

.1080

.1440

.1730

.1980

.2240

.2764

.3344

.3911

.4500

42Y s "24168CMSY

291981

17/64"21/64"25/64"29/64"33/64"

'Clearance drill makes hole with standard clearance for diameter of nominal size.

II


27/32

TH READ C UTTI N G 5 352 MANUAL OF LATHE OPERATIONTABLE XVIII-GEAR SET-UPS TO OBTAIN PROPER

CARRIAGE FEEDS:FOR WINDING WITHENAMEL COVERED MAGNET WIRE

TABLE XVII-GEAR SET-UPS TO OBTAIN PROPERCARRIAGE FEEDS FOR WINDING WITH AMERICAN

STEEL AND WIRE MUSIC WIRE GAUGEThe American S & W gauge is universal for denoting sizesof music wire used in making small springs. Set-ups whichcall for "Position D" require a special extension bracketassembly available from the factory. Extra gears are alsoavai lable from factory at nominal cost.

Accurate to Commercial Tolerances. Set-up for B & SGauge No. 28 requires a special extension bracket assemblyavailable from the factory. Extra gears are also available

from factory at nominal cost.A. S. & W. Wire Gear on Position C Position B Position A Position D CompoundGauge No. Diameter Screw B F B F B F B F TGn,:~~er Note1 ' - I!

Posit ion A Posit ion D CompoundB F B F TG~~;er NoteB&SGauge No.

WireDia.

Gear onScrew

Posit ion CB F

Posit ion BB F

5/05 / 04/03 /02/0o12345678910111213141 516171 819202122232425262728293D31323334

.004.005.005.007.008.009.010.011.012.013.014.016.018.020. 0 2 2.024.025.029.031.033.035.037. 0 3 9.041.043.045.047.049. 0 5 1.055.059.063.067.071.075.080. 0 8 5.090.095.100

64F64F64B64F64B64B64B55B64B44B44F52F54B40B55F54F48F48F56F56F52F54B40F40F56B40F36F36F64B20B40F24B20F24F20F20F20F40F24F20B

52 2054 3220 5246 3620 5220 462 0 523 2 5240 523 2 563 6 2448 2 0

24 36 xxS 4813 6 5648 24481 xxS 3 2 5554 3648 3 248 40xxS 64 1xxS 641xxS 64148 52 xxS 461561 xxS

45 40 xxS 48132 40 xxS 641541 xxS

561 xxS551 xxS561 xxS541 xxS541 xxS56! xxS

(*)616321 53 2323216161616321616323232323232323 2323 2163 23 23 2323 2323 23 23 23 2323 23 23 232

641 xxS44 5254 6 446 54 52 1 xxS36 54 481 xxS6 4 54

48F32F36F40FS6F36F48B46F48F56F64F44F52B48B64B56B54F5GB52B46B45F48BMB64B56F56B54B64F64F

1 213141 5161 7181920212 223242 5262 7282 93031323334353637383940

.0828.0740.0650.0588.0534.0468.0417.0368

20 40xxS 561xxS 56132323232

(*)

32323 2323 23232321 51 61616163 2161616163 232

xxS 52 ! 641 xxSxxS 56! 52 44(*) 40 32 541 xxS48 40.54 46xxS 541 46 24xxS 561xxS 561

52 48 xxS 561xxS 64156 40 xxS 6 4!46 44xxS 56124 54

. 0 3 3 3.02 98

.0266.0237

. 0 2 1 2.0189.0169.0152

.0135.0122.0108.0097.0087.0077.0069.0061.0055.0049.0043.0038. 0 0 3 4

xxS 521d52 3 2

52 403 2 2046 3 246 4052 4844 4046 3644 3 648 2040 3 652 4452 46.36 24441 xxS

44 4040 4446 5446 2 420 5636 6 4561 xxS48 24 32 4056! xxS20 5624 56

(*)h41 xxS 561 xxS561 xxS axxS 641

561 xxS561 xxS56 ! xxS44 4864 56521 xxS56 5254 3654 4664 4840 3 252 44641 xxS56 6 4641 xxS

xxS 40120 5452 3244 20xS 4012 0 3 2

46 54xxS 321*c 6 4 3 2

20 5620 56

32 5252 2 052 2024 442 0 46

163 2321616

chc1

40 44xxS 56 !xxS 52 !xxS 56!xxS 56!xxS 561xxS 561561 20S

54 246 4 32

20 36 SYMBOLS:c-extra 20 tooth geard-extra 40 tooth gearI-extra 2 4 tooth gearh-extra 56 tooth gear"-extra sleeve, bushing and boltassembly

F-position away from headstockB-position toward headstockI-idler gearxxS-steel spacerC"')-special extension bracketassembly

SYMBOLS:c-ext"ra 20 tooth geard-extra 40 tooth gear"-extra sleeve, bushing and boltassembly

F-position away from headstockB-position toward headstockI-idler gearxxS-steel spacer(*)-special extension bracket assembly


28/32

B & S Wire Gear on Position C Posi tion B Posit ion A Posit ion D Compound Compoundumbler Note W&M Wire Gear on Posit ion C Posit ion B Posit ion A Posi tion DGauge No. Di.ameter Screw B F B F B F B F Gear Gauge No".Diameter B B F Tumbler NoteScrew B F F B F Gear12 .080808 64F 20 52 54! xxS 32 1 2 .1055 32F 32 54 641 xxS 3213 .071961 32F 40 46 54! xxS 32 13 .0915 24F 40 44 64I xxS 3214 .064084 24F xxS 56! 52 40 32 14 .0800 20F xxS 52 ! 40 32 3215 .057068 20F xxS 541 56 32 32 15 .0720 20F xxS 54! 64 46 3216 .050820 32F xxS 561 64 52 32 16 .0625 32B 641 xxS 56 1 20S 3217 .045257 32B 44 56 52 48 32 17 .0540 48F 40 52 461 xxS 3218 .040303 46F 55 52 641 xxS 32 18 .0475 55F 35 48 541 xxS 3219 .035890 45F 56 46 641 xxS 32 g 19 .0410 40F 44 36 641 xxS 3220 .031961 48F 52 40 641 xxS 32 641 xxS 3221 .028462 64F 44 40 481 xxS 32 20 .0348 40F 46 3222 .025347 46B 56 48 xx S 641 16 21 .0317 36F xxS 641 56 32 3223 .022571 36B 52 64 xxS 541 16 22 .028 6 64F 48 44 3223 .0258 36B 52 56 xxS 641 1624 .020100 64F 56 36 641 xxS 3225 .011900 48F xxS 641 56 24 32 24 .0230 46B 40 64 52 44 3226 .015940 64B 20 32 xxS 361 54 44 32 25 .0204 56F 56 32 541 xxS 32 h27 .014195 64F 44 20 641 xxS 32 26 .0181 48F 46 20 641 xxS 3221 .0173 52B 35 40 xxS 641 1628 .012641 44B 20 36 xxS 56 ! 1629 .011257 44B 20 40 - xxS 641 16 28 .0162 56F 44 20 64 ! xxS 3230 .010025 S2B 24 46 xxS 641 15 29 .0150 64B 46 48 xxS 54! 1531 .008928 64B 32 56 xxS 54! 16 30 .0140 56B 44 56 xxS 64! 16 h

56B 24 54 xxS 641 16 31 .0132 64B 44 52 xxS 54! 1532 .00795033 .007080 64B 20 44 xxS 541 16 32 .0128 64B 36 44 xxS 641 1534 .006304 64B 20 56 64 36 32 33 .0118 44B 24 46 xxS 641 1635 .005614 52F 56 36 461 xxS 20 44 16 (*) 34 .0104 64B 24 36 xxS 641 16< 55 16 35 .0095 40F 35 24 441 xxS 32 56 16 *6 .005000 64F 64 32 3531 .004453 64.F 64 32 32 56 16 .0090 52F 48 20 32 xxS 461 15 (*)38 .003955 56F 54 24 24 48 16 f 36 5437 .0085 48F 56 32 40 56 xxS 521 16 (*)h38 .0080 64B 20 52 54 36 3239 .0075 64B 20 52 64 40 32

SYMBOLS: 40 .0070 64B 24 56 46 24 32 fi-extra 24 tooth gear F-fron1: position, away from head-stock SYMBOLS:g-extra 45 tooth gear B-back position, toward head- f-extra 24 tooth gear F-position away from headstocktock"'-extra. sleeve, bushing and bolt I-idler gear h-extra 56 tooth gear B-position toward headstockassembly xxS-steel spacer "-extra sleeve, bushing and bolt I-idler gearassembly xxS-steel spacer(O)-special extension bracket as sembly

(" ')-speci al ex tens ion bracket a ssembly


TABLE XIX-GEAR SET-UPS TO OBTAIN PROPERCARRIAGE FEEDS FOR WINDING WITH AMERICAN

OR BROWNE AND SHARPE WIRE GAUGEThis gauge is universal for denoting size of copper, br sss,bronze, aluminum wire, small brass tubing, sheet and stripbrass and copper, nickel silver wire and strip, heating alloywire and armature binding wire. The table below includes, bare wire only.Set-up for B & SGauge No. 35 requires a special extensionbracket assembly available from the factory. Extra gearsare also available from factory at nominal cost.

THREAD CUTTING

TABLE XX-GEAR SET-UP TO OBTAIN PROPERCARRIAGE FEEDS FOR WINDING WITH WASHBURN

AND MOEN OR STEEL WIRE GAUGEThis gauge applies to practically all types of iron and steelwire except steel music wire. Galvanized iron wire, stovepipe and soft iron wire, binding wire, and steel wire forsprings (except music wire) are specified in this gauge.

Set-ups for W & M Gauge Nos. 36 and 37 re-quire a special extension brscket assemblyavailable from the factory. Extra gears arealso available from factory at nominal cost.

55


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5 6 MANUAL OF LATHE OPERATION TH RtAD C UTTI N G 57TABLE XXI-GEAR SET-UPS TO OBTAIN PROPER TABLE XXII-GEAR SET-UPS TO OBTAIN PROPERCARRIAGE FEEDS FOR WINDING WITH DOUBLE CARRIAGE FEEDS FOR WINDING WITH SINGLECOTTON COVERED MAGNET WIRE COTTON COVERED MAGNET WIRE

Accurate to Commercial Tolerances. Accurate to Commercial Tolerances.Set-ups for B & S Gauge Nos. 36 and 37 require a specialextension bracket assembly available from the factory. Ex-B & S Wire Gear on Position C Posit ion B Posit ion A Compound tra gears are also available from factory at nominal cost.umbler NoteGauge No. Diameter Screw B F B F B F Gear

44F 20 40 641 xxS 32 B & S Wire Gear on Posit ion C Posi ti on B Posi tion A Position D Compound12 .0908 Tumbler Note44F 36 64 641 xxS 32 Gaug e No. Diameter Screw B F B F B F B F Gear13 .0810H .0731 32F 48 56 641 xxS 3215 .0661 36F 54 64 641 xxS 32 12 .0858 56F 20 48 641 xxS 3213 .0765 24F xxS 641 48 44 3216 .0598 32F xxS 641 46 44 3 2 14 .0686 32F xxS 641 40 44 3217 .0543 32F xxS 641 46 40 3 2 15 .0616 20F xxS 641 52 3 2 3218 .0493 36F xxS 641 54 48 32 16 .0553 32F xxS 641 52 46 3219 .0444 40F xxS 64! 54 48 32 17 .0498 46F xxS 54! 56 64 3218 .0448 32F xxS 641 56 40 3220 .0410 36F xxS 641 54 40 32 19 .0399 40F 40 32 64! xxS 32 d21 .0365 64F 48 56 32

.0334 48F 40 32 641 xxS 32 20 .0365 48F xxS 5.2I 64 56 32I . ' 22 56F 40 641 xxS 3248 32 h 21 .0325 4423 .0306 56F 56 22 .0294 40B 32 46 52 44 32641 :uS 32 23 .0266 52F xxS 481 52 36 32 p24 .0281 64F 40 36

25 .0259 56F 44 32 641 xxS 32 24 .0241 40B 54 56 xxS 641 1626 ..0239 40B 44 46 xxS 641 16 25 .0219 44B 54 56 xxS 641 1627 .0222 54F 40 24 641 xxS 32 26 .0199 48B 44 46 xxS 641 1627 .0182 64B 44 64 52 44 32 t28 ..0206 56B 46 40 xxS 64I 16 56B xxS48I 52 56 168 .016629 .0193 46B 32 36 xxS 64I 16 29 .0153 56B 48 56 xxS 461 1630 .0180 648 46 40 xxS 4BI 16 30 .OHO 56B xxS 641 44 56 16 h31 .0169 64B 52 48 xxS 56I 16 31 .0129 54B 32 46 xxS 641 1632 .0160 52F 48 20 561 xxS 32 32 .0120 64B 40 52 xxS 641 16

.0151 56B 44 52 xxS 641 16 33 .0111 40B 641 xxS 24 54 163 54B 20 36 xxS 641 . 164 .010334 .0143 40B 481 xxS 3 2 56 16 35 .0096 64B 32 52 xxS 64! 1635 .0136 64F 46 20 641 xxS 3236 .0090 52F 64 48 20 32 xxS 461 16 (*)36 .0130 44B 32 56 xxS 641 16 37 .0085 48F 56 32 40 56 xxS 521 16 h(*)37 .0125 40B 56I xxS 32 64 16 38 .0080 64B 20 52 54 36 3238 .0120 64B 40 52 xxS 64! 16 39 .0075 64B 20 52 64 40 3240 .0071 64B 20 44 xxS 641 1639 .0115 40B 641 xxS 24 52 16

40 .0112 64B 40 56 xxS 641 16SYMBOLS:

SYMBOLS: d-extra 40 tooth gear F-position away from headstockF-position away from headstock h-extra 56 tooth gear B-position toward headstockh-extra '56 tooth gear available p-extra 52 tooth gear 1~i.dler gearfrom facto ry B-position toward he adst ock t-extra 44 tooth gear xxS-steel spacerxxS-steel spacer 1-idler gear (*)-special extension bracket assembly


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TABLE XXIII-GEAR SET-UPS TO OBTAIN PROPERCARRIAGE FEEDS FOR WINDING WITH DOUBLE

SILK COVERED MAGNET WIREAccurate to Commercial Tolerances.

Set-ups fOT B & S Gauge Nos. 36 and 37 require a specialextension biscket assembly available from the factory. Ex-tra gears are also available from factory at nominal cost.

Position C Position B Position A Position D CompoundB F B F B F B F TLG::~~er Note- - - - - - - - - - - - - - - - - - - - -

B & SWireGauge No. Diameter

1213141516171819

.0848

.0760

.0681

.0611

.0548

.0493.0443.0394

Gear onScrew

20F xxS 64124F xxS 64124F xxS 64!20F xxS 64132 xxS 64135F xxS 54136F xxS 64146F 44 4048F44F54F54F40B44B48B64B

52 4448 4444 .3652 3264 5654 4840 3 2641 xxS

xxS 54156 40H40

6 4 56641 xxS641 xxS54 46

54 5654 5644 4644 64

xxS 641xxS 641xxS 64 152 4452 5648 56xxS 641xxS 641xxS 64124 54xxS 641xxS 64120 32 xxS 46I40 56 xxS 52154 3664 40xxS 641

3 23 23232323 2323232323 2321616163216161616161616161516323216

(*)(")

202 12223

.0360.0325.0284.0266.0241.0219.0199. 0 1 8 2.0166.0153.0140.0129. 0 1 2 0.0111.0103.0096.0090.0085.0080. 0 0 75.0071

56B xxS 48156B xxS 46156B 44 5654B 32 4664B40B54B64B52F48F64B64B6413

40 52641 xxS20 3632 5264 4856 3 220 5220 5220 44

2425262728293031323 334353637383940

SYMBOLS:h~extra 56 tooth geart~extra 44 tooth gear( '1 ')~special extension bracket

assembly

F-position away from headstockB~position toward headstockl~idler gear.xxS-steel spacer

h

THREAD CUTTING 59

TABLE XXIV-GEAR SET-UPS TO OBTAIN PROPERCARRIAGE FEEDS FOR WINDING WITH SINGLE SILK

COVERED MAGNET WIREAccurate to Commercial Tolerances.

Set-ups for B & S Gauge Nos. 34, 35 and 36 require a specialextension bracket assembly avai lable from the factory. Ex-tra gears are also available from factory at nominal cost.

B & SWireGauge No+ Diameter

Gear onScrew

Position C Position B Position A Pcsi tion D CompoundB F B F B F B F T'Ge~;r Note

12131415

.0828.0740

.0661

.0591

54F54F56F56F40B48B56F.56B

20F xxS 64120F xxS 54!36F 54 6 440F 46 54

3 23 23 232161 71819

.0528.0473.0423

.0374

.0340.0305

.0274.0246.0221.0199.0179.0162. 0 1 4 6.0133.0120.0109.0100.0091.0083. 0 0 7 6.0070. 0 0 6 5.0060.0055.0051

48 4054 40541 xxS521 xxS32F xxS 64135F 54 4640F 52 4444F 56 46

52 44641 xxS641 xxS641 xxS

323232323 2323 232

202 12 22 3242 526272 82930313 23334353 637383940

48 4456 4652 406 4 4446 5244 4620S 32140 44

641 xxS64I xxS641 xxS641 xxSxxS 641xxS 641xxS 641xxS 641

1616161616321 616

44B 36 5664B 24 4864B 40 5246B 20 40

xxS 64154 46xxS 641xxS 64164B48B64F56F

20 5220 4640 2440 2 046 3620 4820 526 4 3 264 32

48 40xxS 64146 52 xxS 48146 54 xxS 481481 xxS 32 56xxS 64148 2432 5232 56

321616161616321616

64F64B64B56F56F h

SYMBOLS:h-extra 56 tooth gear(" ')~ex tension bracket assemblyxxS-steel spacer

F-position away from headstockB-position toward headstockl~idler gear


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TABLE XXV-GEAR SET-UPS TO OBTAIN PROPERCARRIAGE FEEDS FOR WINDING WITH ENAMELAND, SINGLE COTTON COVERED MAGNET WIRE

Accurate to Commercial TolerancesSet-ups for B & S Gauge Nos. 26 and 32 require a specialextension bracket assembly available from the factory. Ex-tra gears are also available from factory at nominal cost.

B & S Wire Gear onGauge No, Diameter Screw

Position C Position B Position A Position D CornpoundB F B F B F B F T'h".:~!er Note

1213141516171819202122232425262728293031323334353637383940

.0878.0785.0705.0633

.0569.0513.0462.0413

.0378.0338.0306.0277.0252.0229.0209.0192.0175.0162.0148..0137.0127.0117.0109.0101

20F xxS 64120F xxS 64124F xxS 64144F 40 5644F36F40F44F

32 4052 4852 4844 40

64 5656 4452 44481 xxS641 xxS641 xxS641 xxS641 xxS

323232323 23 23 232

.0095.0089.0084.0078.0074

48F 44 403GB 56 4656F3GF 20S 321

641 xxSxxS 64156 48xxS 641

3 2163216321616 (*)16

44F 36 20 641 xxS48B 44 40 xxS 64154B 52 46 xxS 44152F xxS 641

d-extra 40 tooth gearh-extra 56 tooth geart-extra 44 tooth gear"'-extra sleeve, bushing and bolt

assembly

52B 40 4456B 40 4454B 32 4048B 20 3664B48B 36 6446B 20 4054B 24 4440F 36 2464B 3 2 5654B 20 4464B 20 4054F 40 20

xxS 641xxS 641xxS 641xxS 441 54 3252 64 xxS 401xxS 641xxS 641xxS 641

441 xxS 32 56xxS 641xxS 641xxS 64132 40 xxS 441

1616163216 (*)1616161616161616

SYMBOLS:F-position away from headstockB-position toward headstockI-idler gear( '') -special extension bracket

assembly

h

TI-I READ CUTTI NG 61

TABLE XXVI-GEAR SET-UPS TO OBTAIN PROPERCARRIAGE FEEDS FOR WINDING WITH ENAMELAND SINGLE SILK COVERED MAGNET WIREAccurate to Commercial Tolerances. Set-up for B & SGauge No. 25 requires a special extension bracket assemblyavailable from the factory.

B & SWireGauge No. Diameter

Gear onScrew

Position C Position B Position A Position D CompoundB F B 11 ' B 11 ' B '" Tumbler Not.. Gear

12131415.0848.0760.0680.0608

20F xxS 64124F xxS 64 124F xxS 64124F xxS 641S2 444 8 4 454 4444 32

323232321 6171819

.0544.0488.0437.0388

20F36F40F40B

x.xS 64! 36 2064 56641 xxSxiS 641

d*

20212223

.0353.0318

.0286.0257

3 2323 216

cxxS 64154 5655 36

46F 64 52 641 xxS36F 56 32 641 xxS64F 48 4444B 52 46 xxS 641

32323216

24252627.0232.0209.0189.0172

54B 40 32 xxS 64154B 52 46 xxS 44148B 40 44 xxS 64148B 46 56 xxS 6411616 (*)1616

28293031.0155.0142.0128.0117

5GB 40 4664F 44 2064B 36 4448B 36 64xxS 641641 xxSxxS 641xxS 641

16321616

32333435

.0107.0097.0089

.0081

56B 24 4046B 561 xxS64B 32 5656B 20 44

xxS 64124 54xxS 641xxS 641

16161616

3637383940

.0075. o o e e.0064.0051:1.0054,

ME64B6 4 7 r( 1 1 . 1 3!lZI~24 36

64 4052 32xxS 401xxS 64124 48

3232161616

20 5220 561 1 2 3 220 54[;j~ 51

c-extra 20 tooth lil"ll'U' !lVIIIl d,l ,from factory

C')-special extelll l! eu 1111!1 I I I Iassembly

/I' 1 '1 1 "1 1 11 1 11 I lW !l Y L' (: ln ! 1 1 lldHtockI( 1111111.11011 O(l'wII1I1 huudu t ItIl.dllJftll1~ ~I Mill!I~llll I 'I'


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We will assist with your special work by calculatinggear train set-ups for odd threads and feeds notl is ted in Figure 4 (page 5), Table I (pages 38-39),Table II (page 40), or in any of the tables for coil

winding between pages 52 and 61.Address your' inquiry to the Technical ServiceDepartment - it will receive prompt attention.

Threading Information, New Atlas Six-Inch Lathes

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