Frequently Asked Questions - Drill Troubleshooting

Problem	Cause	Solution
Heavy Wear at Outer Edge	Incorrect speed & feed	1, 2
Drill Point Chipping	Loose tool, tool movement Workpiece movement Incorrect speed & feed Drill centering	5, 7, 8, 9, 11, 13, 14 5, 9, 10 1, 2, 3, 4 5, 7, 8, 9
Margin Wear	Poor chip evacuation Workpiece movement	5 5, 10
Tool Breakage	Loose tool, tool movement Workpiece movement Wrong drill type Incorrect speed & feed	5, 7, 8, 9, 11, 13, 14 5, 9, 10 9, 12, 13 1, 2, 3, 4
Poor Tool Life	Incorrect speed & feed Wrong drill point	1, 2, 3, 4 5
Drill Walk	Incorrect speed & feed Tool wear Wrong drill point Material condition	1, 2 5 5, 7, 8 8, 9, 12, 13, 14
Chip Welding	Wrong drill type	14
Hole Size Inaccuracy	Incorrect speed & feed Loose tool Wrong drill type	1, 2, 3, 4 11, 15 6
Non-Cylindrical Hole	Loose tool, tool movement Workpiece movement Incorrect speed & feed Wrong drill type	5, 7, 8, 9, 11, 13, 14, 15 10 1, 2 5
Heavy Burr	Incorrect speed & feed Incorrect drill point	1, 2 5
Blue Chips	Tool wear	5
Long Chips	Poor point grind Incorrect speed & feed	5 1, 2

1) Reduce RPM
2) Increase feed
3) Increase RPM
4) Reduce feed
5)Repoint drill

6) Correct drill type/size
7) Use self-centering drill
8) Spot/center drill
9) Clean surface
10) Improve rigidity/clamp

11) Tighten holder
12) Use straight flute
13) Use stub length
14) Use parabolic design
15) Place further up holder