Feed rate is too fast.

Cutting amount is too great & straining the tool.

Too much overhang of the end mill.

Tool is inappropriate for the application.

Reduce the feed rate.

Reduce width and depth of cuts.

Hold end mill shank deeper in the toolholder or use shorter end mill to create more rigidity.

Check feed rate, speed, coating and method of milling to verify the tool is right for the application (contact our tech team for tool selection assistance).

Speed and feed rate is too fast.

Lack of rigidity.

Too much relief angle.

Cut is too deep.

Correct speed and feed (follow manufacturer recommendations or contact our tech team)

Utilize a machine and/or toolholder that has better rigidity.

Change to an end mill with a smaller relief angle.

Decrease width and depth of cut.

Use a shorter end mill or hold end mill shank deeper in the toolholder.

Feed rate is too fast on first cut.

Feed rate is too fast.

Lack of rigidity (machine & toolholder).Lack of rigidity (workpiece).

Tool corner is too sharp.
Re-cutting chips.

Reduce feed rate on first pass.

Reduce feed rate.

Utilize machine & toolholder with better rigidity.
Secure workpiece more firmly.
Use a shorter end mill (with radius).
Use end mill with radius if applicable.

Chip Packing

Cut is too heavy.
Not enough chip clearance.
Not enough coolant.

Decrease width of cut.
Use end mill with less flutes.
Use a high pressure cooling arm, adjustable coolant hose or coolblast system to direct coolant at the point of cut (or use a cold air gun instead of coolant to disperse chips).
Change the speed and feed to change chip size (use more coolant or a cold air gun to clear away chips).

Hard work material.
Speed is too fast.

Feed rate is too slow.

Wrong helix angle.

Primary relief angle is too large.

Utilize a coated end mill.

Decrease spindle speed and use more coolant.

Increase the feed and speed rate to manufacturer's recommendations.

Change to end mill with appropriate helix angle.

Select end mill with smaller relief angle.

Leaving Burrs

Too much wear on primary angle.

Incorrect speeds and feeds in use.

Correct cutting parameters.

Poor Finish

Feed rate is too fast.

Milling speed is too slow.

Reduce feed rate.
Increase RPM.
Change tool sooner than later.
Change the speed and feed to change chip size (use more coolant or a cold air gun to clear away chips).

Short Tool Life

Cutting friction is too great.

Hard work material.

Check feed rate, speed and change end mill sooner.

Use coated end mills.

Decrease width of cut.
Use end mill with less flutes.
Use a high pressure cooling arm, adjustable coolant hose or coolblast system to direct coolant at the point of cut (or use a cold air gun instead of coolant to disperse chips).