ReamerDEFINITION

Burnishing Reamer

NOMENCLATURE

TROUBLESHOOTING

Reamer is a multi point cutter for enlarging a predrilled hole to obtain accurate size and high surface finish.Reamer produces a hole with in 10 microns.Allowance between drilling to reaming is kept 0.2-0.3 mm in radius.Reamer material can be HSS , Carbide, Coated Carbide and Diamond.Diamond reamers can be used at high speed and high feed for high production.Diamond reamers should be handled carefully due to low toughness.For best quality holes Burnishing reamers are used.

Burnishing reamer is special six flute reamer to produce straight and accurate holeChamfer is provided on every alternate edge to produce 3 burnishing edgesBurnishing edge are made 20 microns plus than cutting edgeBurnish edge removes the high point and presses the work piece material thereby producing high surface finish and accuracy

MILLING CUTTERDEFINITION

NOMENCLATURE

MILLING - Conventional vs Climb

TROUBLESHOOTING

Conventional / Up Milling

Climb / Down Milling

A milling cutter is a rotary tool designed for generating a machined surface by progressively removing a predetermined amount of material or stock from the workpiece.

Conventional / Up Milling

Feed Movement is opposite to tool rotation

Climb / Down MillingFeed Movement and tool rotation have same direction

TAPDEFINITION

TAP NOMENCLATURE

TROUBLESHOOTING

A tap is a special type ofrotary tool designed for the purpose of cutting threads inside the holes.Tapping operation is done after drilling operation. A required size of stock is needed for cutting the threads inside the holes

DRILLDEFINITION

DRILL NOMENCLATURE

POINT ANGLE EFFECTS

WEB THICKNESS EFFECTS

EFFECTS OF REGRINDING

TROUBLESHOOTING

A drill is a rotary-end cutting tool with one or more cutting edges or lips and one or more straight or helical grooves called flutes, designed for the passage of chips, cutting fluids and coolants

Resharpening a twist drill results in increasing the web thickness and chisel edge length and decreases the drill diameter

Problem Cause

Chip packing

Galling

Hole size

Galling

Incorrect tap

Left-over chips

Breakage

Incorrect tap selection

Excessive tapping torque

Operating conditions

Chipping Incorrect tap selection

Operating conditions

Oversize Pitch Diameter

Oversize internal Diameter

Undersize Pitch Diameter

Solution1. Use spiral point or spiral fluted taps.2. Reduce number of flutes to provide extra chip room.3. Use larger hole size.1. Apply proper surface treatment such as steam oxide or TiN.2. Reduce tapping speed.3. Use larger hole size.1. Use minimum hole size.2. Avoid tapered hole.1. Apply proper surface treatment such as steam oxide or TiN.2. Use proper cutting lubricant.

1. Increase cutting performance to avoid any left over chips in the hole.2. Remove left over chips from the hole for gage checking.

2. Apply correct surface treatment such as steam oxide or TiN.1. Use larger drill size.2. Use a tap with more thread relief and reduced land width.3. Use spiral pointed or spiral fluted taps.1. Reduce tapping speed.2. Avoid misalignment between tap and the hole and tapered hole.3. Use floating type of tapping holder.1. Reduce cutting angle.2. Reduce hardness of the tap.3. Increase chamfer length.1. Reduce tapping speed.2. Avoid misalignment between tap and hole.3. Avoid sudden return of reverse in blind hole tapping.

1. Use oversize taps for cutting materials such as copper alloy, aluminum alloy, and cast iron.2. Use oversize taps for cutting tubing which will have "spring back" action after tapping.

1. Avoid chip packing in the flutes or the bottom of the hole. Use spiral pointed or spiral fluted taps or fluteless taps.

PROBLEM CHATTER (lines or grooves at regular intervals) Excessive cutting force Use sharp edge inserts; avoid hone or T-landThin-walled part PROBLEM POOR SURFACE FINISH - Roughness Built-up edge High tooth Wiper insert set too high PROBLEM

POOR SURFACE FINISH - Flatness

Improper spindle tilt (milling machines) Excessive cutting force Width of cut too large for cutter

PROBLEM POOR SURFACE FINISH - Waviness Reduce feed ratePROBLEM PART BURRING Excessive insert edge prep Improper angle of entry or exit of cutter Improper lead angle Chip load too great or too small PROBLEM WORKPIECE BREAKOUT Use inserts with double facet cornersImproper angle of entry or exit of cutter PROBLEM POOR INSERT LIFE - Flank Wear Use coolantIncorrect grade PROBLEM POOR INSERT LIFE - Crater Wear Reduce speedFlush with coolantExcessive cutting force

PROBLEM POOR INSERT LIFE - Built-up Edge Use coolant to aid lubricityUse sharp edge insertsUse grades with high lubricity surfaces (PVD coated grades, Cermet grades, polished carbide grades)PROBLEM POOR INSERT LIFE - Chipping Reduce feed rate, depth of cut or width of cut if excessiveUse sharp edge inserts; avoid hone or T-landInsufficient edge prep Incorrect grade Built-up edge Excessive cutting force Re-cutting chips Use air blast or coolant to remove chips.PROBLEM POOR INSERT LIFE - Depth of Cut Notching Use more wear resistant gradeReduce feed per toothReduce speedUse T-landVary depth of cutPROBLEM POOR INSERT LIFE - Thermal Cracks Use cutter with more positive geometryUse grade designed for use with coolantDiscontinue coolant use

CAUSES Lack of rigidity Reduce feed rate, depth of cut or width of cut if excessive

Dampen partCAUSES Insert worn Increase speed, use PVD coated inserts, use coolantCorrect improper preset. Set wiper.0005" to .002" above high insertCAUSES

Deflection

Check spindle tilt - .0015" per foot is recommendedUse a more positive rake cutterUse a larger diameter cutter

CAUSES Advance per revolution greater than width of flat of insert

CAUSES Insert worn Reduce or avoid hone or T-landChange position of center of cutter over partUse larger lead angle; avoid 0 lead angle cuttersIncrease or decrease chip loadCAUSES Improper geometry

Change position of center of cutter over partCAUSES Excessive heat

Use a more wear resistant coated gradeCAUSES Excessive heat

Reduce feed rate

CAUSES Insufficient cutting temperature causes chip adherence to insert

CAUSES Chatter

Use hone or T-landUse tougher gradeIncrease speed, use PVD coated grade, use coolantDecrease feed per toothUse cutter with chip gullets large enough for chip clearance.

CAUSES Scale part, high work hardening materials

CAUSES Heat stresses due to temperature variations

SOLUTIONSCheck spindle & fixture rigidity

SOLUTIONSUse more wear resistant coated grade

SOLUTIONS

Check for deflection of part, cutter or spindle

SOLUTIONSDeflection

SOLUTIONSUse more wear resistant coated grade

SOLUTIONSUse larger lead angle; avoid 0 lead angle cutters

SOLUTIONSReduce speed. Increase chip load to carry away heat

SOLUTIONSUse a more heat resistant coated grade (Al2O3 layer)

SOLUTIONSIncrease speed

SOLUTIONSCheck spindle & fixture rigidity

SOLUTIONSUse larger lead angle; avoid 0 lead angle cutters

SOLUTIONSReduce speed

Problem Cause

Chipping

Feed rate too high

Up milling (conventional)

Cutting edge too sharp

Chattering

Loose tool

Workpiece rigidity

Tool rigidity

Low cutting speed

Loose toolholder

Breakage

Excessive spindle TIR

Feed rate too high

Depth of cut too large

Poor tool rigidity

Tool wear

Poor chip evacuation

Chattering

Speed and feed too high

Poor toolholder rigidity

Poor spindle rigidity

Workpiece rigidity

Relief angle too high

Depth of cut too large

Poor tool rigidity

Chip PackingFeed rate too high

Low cutting speed

Insufficient chip room

SolutionReduce feed rate

Change to down milling (climb)

Hone cutting edge or allow break-in

Reduce RPM

Remove, clean, and retighten

Tighten workpiece holding method

Shorten LOC, place shank further up holder

Increase RPM

Remove from spindle, clean and replace

Reduce feed rate

Reduce depth of cut

Shorten LOC, place shank further up holder

Replace/regrind sooner

Use air blasting

Reduce feed rate

Replace with shorter/more rigid holder

Use larger spindle or different machine tool

Tighten workpiece holding method

Regrind with smaller relief angle

Reduce depth of cut

Shorten LOC, place shank further up holder

Reduce feed rate or increase speed

Increase RPM or reduce feed rate

Use tool with less flutes, increase helix

ReamermilltapdrilSheet1Sheet2