Slip gauges
-
Upload
leo-dev-wins -
Category
Documents
-
view
219 -
download
0
Transcript of Slip gauges
-
8/12/2019 Slip gauges
1/37
1
Gage Blocks
Session 2
-
8/12/2019 Slip gauges
2/37
2
Gage Blocks
Accepted standard of accuracy
Provides industry with means of
maintaining sizes to specific standardsor tolerances
Has led to higher rates of production
Makes interchangeable manufacturepossible
-
8/12/2019 Slip gauges
3/37
3
Gage Block Manufacture
Blocks of hardened and ground alloy
steel
Stabilized through alternate cycles of
extreme heat and cold
Crystalline structure of metal left without
strain
Solid Cemented Carbide Ceramic
-
8/12/2019 Slip gauges
4/37
4
Gage Block Manufacture
Two measuring surfaces machined,
ground, lapped and polished to an
optically flat surface
Use optical flats to determine flatness
Made to a specific size
Accurate within range of 1 8 millionths of
inch
Accurate within range of 25 200 millionths
mm
-
8/12/2019 Slip gauges
5/37
5
Gage Block Manufacture
Size of each block marked on surface
Final calibration done where temperaturemaintained at 68F or 20 C.
Considered accurate to size only whenmeasured at this temperature
Available square, rectangular, and round
-
8/12/2019 Slip gauges
6/37
6
Gage Blocks
Ceramic
Verses
Alloy
-
8/12/2019 Slip gauges
7/37
7
Steel Block Advantage
Lower Cost
Good abrasion resistance 1/10 xceramic
Good Thermal expansion coefficient
Resistant to impact
Free from chipping
Wring together tightly
-
8/12/2019 Slip gauges
8/37
8
Ceramic Block Advantage
Corrosion resistant
No detrimental effects as a result ofhandling
Superior abrasion resistance 10 x steel
Good Thermal expansion coefficient
Resistant to impact
Free from burrs
Wring together tightly
-
8/12/2019 Slip gauges
9/37
9
Carbide Block Advantage
Corrosion resistant
No detrimental effects as a result ofhandling
Superior abrasion resistance 10 x steel
Good Thermal expansion coefficient
Free from burrs
Wring together tightly
-
8/12/2019 Slip gauges
10/37
10
Gage Block Uses
To check dimensional accuracy of fixedgages to determine extent of wear,growth, or shrinkage
To calibrate adjustable gages To set comparators, dial indicators, and
height gages to exact dimensions
To set sine bars and sine plates whenextreme accuracy required in angularsetups
-
8/12/2019 Slip gauges
11/37
11
Gage Block Uses
For precision layout with use of
attachments
To make machine tool setups
To measure and inspect accuracy of
finished parts
-
8/12/2019 Slip gauges
12/37
12
Inch Standard Gage Blocks
Sets range from few blocks to as many as115
Most common is 83-piece set
Can make over 120,000 differentmeasurements
-
8/12/2019 Slip gauges
13/37
13
Inch Gage BlocksTwo 0.050 inch wear blocks supplied
with some setsUsed at each end of build-up
Wear occurring during use will be onthese only
Good practice to always expose same
face of wear block to work surface
Prolongs life and accuracy ofset
-
8/12/2019 Slip gauges
14/37
14
Metric Gage Blocks
Supplied in sets of 47, 88, 113 blocks
Most common is 88-piece set
Each set contains pair of 2 mm wearblocks
Used at end of buildup to prolong accuracy
of other blocks
-
8/12/2019 Slip gauges
15/37
15
Degrees of Accuracy
Class AAA (Master laboratory set)
Also listed as Grade .5
Accurate to .000001 in. or 0.000025
mm.
Used in environmentally controlled labs
as master references for other gage
blocks
-
8/12/2019 Slip gauges
16/37
16
Class AA (laboratory or master set)
Also listed as Grade 1
Accurate to .000002 in. or 0.00005
mm.
Used in temperature controlled labs as
references
Degrees of Accuracy
-
8/12/2019 Slip gauges
17/37
17
Class A (inspection set)
Also listed as Grade 2
Accurate to .000004 in.
and +0.00015 mm. and -0.00005 mm.
Used for inspection purposes
Degrees of Accuracy
-
8/12/2019 Slip gauges
18/37
18
Class B (working set)
Also listed as Grade 3
Accurate to .000008 in.
and +0.00025mm. and -0.00015 mm.
Used in shop for setups, layouts and
measurement
Degrees of Accuracy
-
8/12/2019 Slip gauges
19/37
19
Effect of Temperature
Temperature changes important when
handling
Calibrated at 68F or 20C
Human body temperature 98F
One degree F rise will cause a four
inch stack of gage blocks to expand
.000025 in.
Handle as little as possible!
-
8/12/2019 Slip gauges
20/37
20
Temperature-ChangeErrors Handle only when they must be moved
Hold by hand for as little time as possible
Hold between the tips of fingers so thatarea of contact is small
Have the work and gage blocks at thesame temperature
Where extreme accu racyis necessary,use insulating gloves and tweezers
-
8/12/2019 Slip gauges
21/37
21
Gage Block Accessories
-
8/12/2019 Slip gauges
22/37
22
Gage Block Accessories
-
8/12/2019 Slip gauges
23/37
23
Gage Block Accessories
-
8/12/2019 Slip gauges
24/37
24
Gage Block Constructions
-
8/12/2019 Slip gauges
25/37
25
Gage Block Build-up
1 Write dimension on paper
2 Deduct size of two wear blocks3 Use block that will eliminate right
hand digit (Deduct 0.1006)
4 Use block that will eliminate right
hand digit (4) and at same time bring digit
to left of it (9) to zero or a five
5 Continue to eliminate digits from right
to left until dimension required attained
3.7946
(2 x .0500 in. = .1000 in.)
-0.1000
3.6946
-0.1006
3.594
(0.144)
-0.144
3.450
(0.450 block) Repeat with 3.000 block
-0.4503.000
-3.000
0.0
-
8/12/2019 Slip gauges
26/37
26
Gage Block Build-up
1 Write dimension on paper
2 Deduct size of two wear blocks3 Use block that will eliminate right
hand digit (Deduct 0.1008)
4 Use block that will eliminate right
hand digit (2) and at same time bring digit
to left of it (4) to zero or a five
5 Continue to eliminate digits from right
to left until dimension required attained
1.6428
(2 x .0500 in. = .1000 in.)
-0.1000
1.5428
-0.1008
1.4420
(0.142)
-0.142
1.300
(0.300 block) Repeat with 1.000 block
-0.3001.000
-1.000
0.0
-
8/12/2019 Slip gauges
27/37
27
Gage Block Buildups
Clean blocks with clean, soft cloth
Wipe each contacting surface on cleanhand palm or on wrist
Place end of one block over end ofanother block
While applying pressure, slide oneblock over other
Note: If blocks do not wring together, itis generally because blocks have notbeen thoroughly cleaned.
-
8/12/2019 Slip gauges
28/37
28
Gage Block Wringing
Adhere to each other so well can
withstand 200-pound pull Atmospheric
pressure
Molecular attraction
Extremely flat surfaces of blocks
Minute film of oil
Combination of all above
-
8/12/2019 Slip gauges
29/37
29
Wringing Gage Blocks
-
8/12/2019 Slip gauges
30/37
30
Wringing Gage Blocks
-
8/12/2019 Slip gauges
31/37
31
Wringing Gage Blocks
-
8/12/2019 Slip gauges
32/37
32
Wringing Gage Blocks
-
8/12/2019 Slip gauges
33/37
33
Care of Gage Blocks
Keep in closed case to protect from dustand dirt
Do not handle unnecessarily
Avoid fingering lapped surfaces Do not drop or scratch their lapped
surfaces
-
8/12/2019 Slip gauges
34/37
34
Care of Gage Blocks
Immediately after use, each blockshould be cleaned, oiled, and replacedin the storage case
Before wrung together, faces must befree from oil and dust
Should never be left wrung together for
any length of time
-
8/12/2019 Slip gauges
35/37
35
Care of Gage Blocks
-
8/12/2019 Slip gauges
36/37
36
-
8/12/2019 Slip gauges
37/37
37