| Problem |
Cause |
Solution |
| Chipping |
Feed is too fast |
Reduce feeds |
|
Loose tool |
Tighten tool |
|
Loose fixture |
Tighten fixture |
|
Tool is not rigid enough |
Shorter end mill |
| Excessive
Wear |
Speed is to fast |
Use slower speed |
|
Feed rate is too
low |
Add coating |
|
Improper cutting
angle |
Increase feed rate |
|
Primary relief angle is too
small |
Use larger relief angle |
| Breakage |
Feed rate is too
fast |
Decrease feed rate |
|
Cutting amount is
too large |
Take smaller cuts
per tooth |
|
Flute length is
excessive |
Shorter flute
length end mill |
|
Too much wear |
Resharpen sooner |
| Chattering |
Feed and speed to
fast |
Adjust speeds and
feeds |
|
Machine holder not
rigid enough |
Use appropriate
holder. Use smaller relief angle |
|
Loose workpiece |
Refixture part |
|
Cut is too deep |
Try shorter flute |
|
Flute length is too long on
end mill |
Try shorter flute length on
end mill |
| Dullness |
Cutting friction is
to great |
Resharpen
sooner |
|
Improper cutting angle |
Adjust primary clearance
angles |
| Chips
packing in flutes |
Cutting
amount is to great |
Modify speeds and
feeds
Choose another end mill |
|
Not enough chip
room |
Use additional
coolant |
|
Insufficient coolant |
Use air flow if possible |
| Rough
surface finish |
Feed rate is too
great |
Decrease feed rate |
|
Speed is too slow |
Increase speeds |
|
Too much wear |
Resharpen sooner |
|
No end teeth concavity |
Add dish to bottom |
| Burr |
Primary relief wear |
Resharpen sooner |
