Surface
Roughness

• Increase chamfer length

• Apply proper cutting angle

• Use thread relieved taps
• Reduce land widths
• Apply surface treatment such as
  steam oxide or chrome
• Use proper cutting lubricant
  Reduce tapping speed
• Use larger drill size
• Obtain proper alignment
  between tap and work

• Use spiral pointed or spiral fluted taps
• Use larger drill size

• Avoid too narrow land width
• Reduce amount of thread relief

• Reduce cuffing angle
• Do not grind bottom of the flute

Dimensional
Error

Dimensional
Error

Dimensional
Error

• Use proper GH limits
• Use longer chamfered taps

• Use spiral point or spiral fluted taps
• Reduce number of flutes to provide extra chip room
• Use national fine pitch, if applicable
• Use larger drill size
• If tapping a blind hole, allow deeper hole where
  applicable or shorten the thread length of the parts
• Use proper lubricant

• Apply proper surface treatment such as steam oxide
• Use proper cutting lubricant
• Reduce tapping speed
• Use proper cutting angle in accordance with material being tapped
• Use larger drill size

• Apply proper tapping speed
• Correct alignment of tap and drill hole
• Free cutting either tap or workpiece
• Use proper tapping speed to avoid torn or rough thread
• Use lead screw tapper

• Obtain proper indexing angle for the flutes at the cutting edge
• Grind proper indexing angle and chamfer angle
• avoid too narrow a width
• Remove burrs from reground edge

• Use minimum size drill hole
• Avoid tapered hole
• Use proper chamfered taps

• Galling solutions 1 through 4 above can be applied to this specific problem

• Use one oversize taps:
  1) Use for cutting materials such as copper alloy, aluminum alloy, and cast iron
  2) Use for cutting tubing witch will have "spring back" action after tapping
• Apply proper chamfer angle
• Increase cutting angle

• Use proper reversing speed to avoid damaging tapped thread the way out of the hole

• Increase cutting performance to avoid any leftover chip in the hole
• Remove leftover chip from the hole for gage checking

• Use maximum drill size

Tool Life

Tool Life

Tool Life

Breakage

• Use high speed steel taps
• Avoid chip packing in the flutes or the bottom of the hole
• Use spiral pointed or spiral fluted taps or roll taps
• Apply correct surface treatment such as steam oxide or other coating

• Use larger drill size
• Try to shorten thread length
• Apply national fine pitch if applicable
• Increase cutting angle
• Apply a tap with more thread relief and reduced land width
• Use spiral pointed or spiral fluted taps

• Reduce tapping speed
• Avoid misalignment between tap and the hole and tapered hole
• Use floating type of tapping holder
• Use tapping holder with torque adjustment
• Avoid hitting bottom of the hole with tap

• Do not grind the bottom of the threads
• Avoid too narrow land width
• Do not leave sections on the reground flutes which tapping wear still remains
• Regrind tool more frequently

• Reduce cutting angle
• Use different kind of high speed steel taps
• Reduce hardness of taps
• Increase chamfer length
• Avoid chip packing in the flutes or the bottom of the hole by using spiral pointed or fluted taps

• Reduce tapping speed
• Avoid misalignment between tap and hole
• Avoid sudden reverse or return in blind hole tapping
• Avoid galling
• Use larger drill size

• Apply specially designed taps for tapping heat treated materials
• Change to a type of high speed steel material containing vanadium
• Apply special surface treatment such as nitriding or TiN
• Increase chamfer length

• Reduce tapping speed
• Apply proper cutting lubricants
• Avoid work hardened hole
• Use larger drill size

• Grind proper cutting angle
• Avoid hardness reduction from grinding process