| Problem |
Cause |
Solution |
|
Over wear on
clearance face
|
Cutting speed too high. |
Reduce cutting speed |
| Low cutting depth, abrasion. |
Reduce frequency of feed and
friction of cutting edge.
|
| Inserts are over the center line |
Adopt correct center height. |
|
Asymmetric wear on
right and left cutting
edge
|
The inclined angle of insert is
different from the helical angle of
thread
|
Change to proper shim to get
correct inclined angle.
|
| Flank in-feed is not correct. |
Change the way of flank in-feed. |
| Breakage |
Cutting speed too low. |
Increase cutting speed. |
| Cutting force too high. |
Increase frequency of feed and
reduce Max in-feed.
|
| Unstable clamping. |
Check if workpiece vibrates.
Reduce overhang of tool.
Verify clamping of workpiece
and tool
|
| Chip twisting. |
Increase the pressure of cooling
liquid to blow away chips
|
| Plastic deformation |
High cutting speed, high
temperature on cutting area
|
Reduce cutting speed.
Increase feed frequency and
reduce Max cutting depth
|
| Insufficient cooling fluid. |
Increase cooling fluid supply |
|
Low thread surface
quality
|
Cutting speed too low.
The insert is over the center line.
Chips are not under control.
|
Increase cutting speed.
Adjust centre height.
Change the operation way of
tools to well control chips.
|
| Incorrect profile |
Incorrect center height. |
Adjust centre height |
| Pitch on machine is not correct. |
Adjust machine. |
| Shallow profile |
Cutting speed set wrong. |
Alter cutting depth |
| Surface damage |
Chips involved or contacted. |
Change to flank in-feed to control chip flow
direction
|
| Built-up edge |
Temperature of cutting edge is too
low.Usually occur when machining
stainlesssteel and low carbon steel.
|
Increase cutting speed as well
as pressure andconcentration of cooling fluid.
Choose inserts with good
toughness
|
| Crack on surface |
Cutting force too high |
Reduce the cutting depth of
each feed.
|
| Vibration |
Incorrect clamping of workpiece or
tool
|
Verify clamping of workpiece
and tool. Minimize overhang
of tool.
|
| Incorrect cutting parameters |
Increase cutting speed or
reduce it substantially.
|
| Incorrect tool clamping |
Adjust center height |
