PROBLEM |
SOLUTION |
Oversize
Pitch Diameter |
Incorrect tap |
1. Use proper GH limits
of taps. |
|
2. Use longer chamfered
taps |
|
Chip packing |
1. Use spiral point or
spiral fluted taps. |
|
2. Reduce number of flutes
to provide extra chip room. |
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3. Use larger hole size. |
|
4. If tapping a blind hole,
allow deeper holes where applicable or shorten the thread
length of the parts. |
|
5. Use proper lubricant. |
|
Galling |
1. Apply proper surface
treatment such as steam oxide or TiN. |
|
2. Use proper cutting lubricant. |
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3. Reduce tapping speed. |
|
4. Use proper cutting angle
in accordance with material being tapped. |
|
5. Use larger hole size. |
|
Operating conditions |
1. Apply proper tapping
speed. |
|
2. Correct alignment of
tap and drilled hole. |
|
3. Use proper tapping speed
to avoid torn or rough threads. |
|
4. Use lead screw tapper. |
|
5. Use proper tapping machine
with suitable power. |
|
6. Avoid misalignment of
the tap and drilled hole from loose spindle or worn holder. |
|
Tool conditions |
1. Obtain proper indexing
angle for the flutes at the cutting edge. |
|
2. Grind proper cutting
angle and chamfer angle. |
|
3. Avoid too narrow a land
width. |
|
4. Remove burrs from regrinding. |
|
PROBLEM |
SOLUTION |
Oversize
Internal Diameter |
Hole size |
1. Use minimum hole size. |
|
2. Avoid tapered hole. |
|
3. Use proper chamfered
taps. |
|
Galling |
1. Apply proper surface
treatment such as steam oxide or TiN. |
|
2. Use proper cutting lubricant. |
|
3. Reduce tapping speed. |
|
4. Use proper cutting angle
in accordance with material being tapped. |
|
PROBLEM |
SOLUTION |
Undersize
Pitch Diameter |
Incorrect tap |
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. |
|
3. Apply proper chamfer
angle. |
|
4. Increase cutting angle. |
|
Damaged thread |
Use proper reversing speed
to avoid damaging tapped thread on the way out of the hole. |
|
Left-over chips |
1. Increase cutting performance to avoid any left over chips
in the hole. |
|
2. Remove left over chips from the hole for gage checking. |
|
PROBLEM |
SOLUTION |
Undersize
Internal Diameter |
Hole diameter |
Use maximum drill size. |
|