| PROBLEM |
CAUSES |
SOLUTION |
| Breakage |
Incorrect Tap Selection |
1. Avoid chip packing in the flutes or the bottom of
the hole. Use spiral pointed or spiral fluted taps or
flute less taps.
2. Apply correct surface treatment such as steam oxide
or TiN. |
| Excessive Tapping Torque |
1. Use larger drill size.
2. Try to shorten thread length.
3. Increase cutting angle.
4. Use a tap with more thread relief and reduced land
width.
5. Use spiral pointed or spiral fluted taps. |
| Operating Conditions |
1. Reduce tapping speed.
2. Avoid misalignment between tap and the hole and tapered
hole.
3. Use floating type of tapping holder.
4. Use tapping holder with torque adjustment.
5. Avoid hitting bottom of the hole with tap. |
| Tool Conditions |
1. Do not grind the bottom of the flute.
2. Avoid too narrow a land width.
3. Remove all worn sections when regrinding the flutes.
4. Regrind tool more frequently. |
| Chipping |
Incorrect Tap Selection |
1. Reduce cutting angle.
2. Use different kind of high-speed steel tap.
3. Reduce hardness of the tap.
4. Increase chamfer length.
5. Avoid chip packing in the flutes or in the bottom of
the hole by using spiral fluted or spiral pointed taps.
|
| Operating Conditions |
1. Reduce tapping speed.
2. Avoid misalignment between tap and hole.
3. Avoid sudden return of reverse in blind hole tapping.
4. Avoid galling.
5. Use large hole size. |
| Wear |
Incorrect Tap Selection |
1. Use specially designed taps for tapping heat treated
material.
2. Change to a type of high-speed steel tap that contains
vanadium.
3. Apply special surface treatment such as steam oxide
or TiN.
4. Increase chamfer length. |
| Operating Conditions |
1. Reduce tapping speed.
2. Apply proper cutting lubricants.
3. Avoid work hardening.
4. Use larger hole size. |
| Tool Conditions |
1. Grind proper cutting angle.
2. Avoid hardness reduction from grinding process. |
