PROBLEM |
CAUSE |
SOLUTION |
Chip
packing
|
Too
great a cutting amount |
Adjust
feed or speed |
Not
enough chip room |
Use
end mill fewer flutes |
Not
enough coolant |
Apply
more coolant. Use air pressure |
|
PROBLEM |
CAUSE |
SOLUTION |
Rough
surface finish
|
Feed
too fast |
Slow
down to correct feed |
Slow
speed |
Use
higher speed |
Too
much wear |
Regrind
earlier stage |
Chip
biting |
Cut
less amount per pass |
No
end tooth concavity |
Add
margin (touch primary with oilstone) |
|
PROBLEM |
CAUSE |
SOLUTION |
Burr |
Too
much wear on primary relief |
Regrind
sooner |
Incorrect
condition |
Correct
milling condition |
Improper
cutting angle |
Change
to correct cutting angle |
|
PROBLEM |
CAUSE |
SOLUTION |
No
dimensional accuracy
|
Too
tough condition |
Change
to easier condition |
Lack
of accuracy (machine & holder) |
Repair
machine or holder |
Not
enough rigidity (machine & holder) |
Change
machine or holder or condition |
Not
sufficient number of flutes |
Use
end mill with greater number of flutes |
|
PROBLEM |
CAUSE |
SOLUTION |
No
perpendicular side
|
Feed
too fast |
Slow
down to correct feed |
Too
great a cutting amount |
Reduce
cutting amount |
Too
long a flute length or long overall length |
Use
proper length tool. Hold shank deeper |
Not
sufficient number of flutes |
Use
end mill with greater number of flutes |
|
PROBLEM |
CAUSE |
SOLUTION |
Chipping
|
Feed
too fast |
Slow
down to proper feed |
Feed
too fast on first cut |
Slow
down on first bite |
Not
enough rigidity of machine tool & holder |
Change
rigid machine tool or holder |
Loose
holder |
Tighten
tool holder |
Loose
holder (workpiece) |
Tighten
workpiece fixture |
Lack
of rigidity (tool) |
Use
shortest end mill available. Hold shank deeper. Try down cut |
Teeth
too sharp |
Change
to lower cutting angle, primary relief |
|
PROBLEM |
CAUSE |
SOLUTION |
Wear
|
Speed
too fast |
Slow
down, use more coolant |
Hard
material |
Use
higher grade, tool material, add surface treatment |
Biting
chips |
Change
feed speed to change chip size or clear chips with coolant or air pressure |
Improper
feed speed (too slow) |
Increase
feed speed. Try down cut |
Improper
cutting angle |
Change
to correct cutting angle |
Too
low a primary relief angle |
Change
to larger relief angle |
|
PROBLEM |
CAUSE |
SOLUTION |
Breakage
|
Feed
too fast |
Slow
down feed |
Too
large cutting amount |
Adjust
to smaller cutting amount per teeth |
Too
long flute length or long overall length |
Hold
shank deeper, use shorter end mill |
Too
much wear |
Regrind
at earlier stage |
|
PROBLEM |
CAUSE |
SOLUTION |
Chattering
|
Feed
and speed too fast |
Correct
feed and speed |
Not
enough rigidity (machine & holder) |
Use
better machine tool or holder or change condition |
Too
much relief angle |
Change
to smaller relief angle. Add margin (touch primary with oil stone) |
Loose
holder (workpiece) |
Hold
workpiece tighter |
Cutting
too deep |
Correct
to smaller cutting depth |
Too
long flute length or long overall length |
Hold
shank deeper, use shorter end mill or try down cut |
|
PROBLEM |
CAUSE |
SOLUTION |
Short
tool life
(dull
teeth) |
Too
much cutting friction |
Regrind
at earlier stage |
Tough
work material |
Select
premium tool |
Improper
cutting angle |
Change
cutting angle & primary |