Troubleshooting

Cause: Too great a cutting amount

Adjust feed or speed.

Cause: Not enough Chip room

Use end mill fewer flutes.

Cause: Not enough coolant

Apply more coolant. Use air pressure.

Cause: Feed too fast

Slow down to correct feed.

Cause: Slow Speed

Use higher speed.

Cause: Too Much Wear

Regrind earlier stage.

Cause: Chip biting

Cut less amount per pass.

Cause: No end tooth concavity

Add margin (touch primary with oilstone).

Cause: Too Much Wear on Primary Relief

Regrind sooner.

Cause: Incorrect condition

Correct milling condition.

Cause: Improper cutting angle

Change to correct cutting angle.

Cause: Too Tough Condition

Change to easier condition.

Cause: Lack of accuracy (machine and holder)

Repair machine or holder.

Cause: Not Enough Rigidity (machine and holder)

Change machine or holder or condition.

Cause: Not Sufficient Number of Flutes

Use end mill with greater number of flutes.

Cause: Feed Too Fast

Slow down to correct feed.

Cause: Too Great a Cutting Amount

Reduce cutting amount.

Cause: Too Long a Flute Length or Long Overall Length

Use proper length tool. Hold shank deeper.

Cause: Not Sufficient Number of Flutes

Use end mill with greater number of flutes.

Cause: Feed Too Fast

Slow down to proper feed.

Cause: Feed Too Fast on First Cut

Slow down on first bite.

Cause: Not Enough Rigidity of Machine Tool and Holder

Change rigid machine tool or holder.

Cause: Loose Holder

Tighten tool holder.

Cause: Loose Holder (Workpiece)

Tighten workpiece fixture.

Cause: Lack of Rigidity (Tool)

Use shortest end mill available. Hold shank deeper. Try down cut.

Cause: Teeth Too Sharp

Change to lower cutting angle, primary relief.

Cause: Speed Too Fast

Slow down. Use more coolant.

Cause: Hard Material

Use higher-grade tool material. Add surface treatment.

Cause: Biting Chips

Change feed speed to change chip size or clear chips with coolant or air pressure.

Cause: Improper Feed Speed (Too Slow)

Increase feed speed. Try down cut.

Cause: Improper Cutting Angle

Change to correct cutting angle.

Cause: Too Low a Primary Relief Angle

Change to larger relief angle.

Cause: Feed Too Fast

Slow down feed.

Cause: Too Large Cutting Amount

Adjust to smaller cutting amount per teeth.

Cause: Too Long Flute Length or Long Overall Length

Hold shank deeper. Use shorter end mill.

Cause: Too Much Wear

Regrind at earlier stage.

Cause: Feed and Speed Too Fast

Correct feed and speed.

Cause: Not Enough Rigidity (Machine and Holder)

Use better machine tool or holder or change condition.

Cause: Too Much Relief Angle

Change to smaller relief angle Add margin (touch primary with oilstone).

Cause: Loose Holder (Workpiece)

Hold workpiece tighter.

Cause: Cutting Too Deep

Correct to smaller cutting depth.

Cause: Too Long Flute Length or Long Overall Length

Hold shank deeper. Use shorter end mill or try down cut.

Cause: Too Much Cutting Friction

Regrind at earlier stage.

Cause: Tough Work Material

Select premium tool.

Cause: Improper Cutting Angle

Change cutting angle and primary.