Page 125 - HOLE MAKING CATALOG p185-310

Drill Problems Hole Problems Gundrill Troubleshooting Guide
Breakage Oversize
Chipping Undersize
Poor drill life Rough surface finish
Excessive margin wear Runout
Excessive corner wear Conical entrance
Excessive flank wear Curved hole axis
Drill heat
Flute bending
Damaged wear pad
Built-up edge
Cratering

+ ++ + + ++++ ++ +++++++ +++++++++++++++++ +++ ++ + +++++++++ +++++++ + ++ + ++ +++++ ++ Poor clamping
Insufficient coolant flow
+ Low coolant pressure
Incorrect coolant type
++ ++++ ++ + + Feed fluctuations
Too high feed
++ + ++ + + Too low feed
Spindle speed too high
+ ++ ++ + ++ + Spindle speed too low
Material structure
++ + + ++ + ++++++++ +++++ + +++++++++ ++ Material shrinking due to heat
Workpiece thin wall section
+ Misalignment
Undersized hole
+ ++ ++ + + + +++++ + ++ +++ Rough cutting edge finish
Built up edge
++ ++ +++ ++++ + + + ++ + +++ +++ + + ++++++ Worn out edgePossible Causes
Interrupted chip flow
+++ + + +++ + ++ + Too small flute clearance
Incorrect drill profile
+++ +++ +++ ++++ + ++ Incorrect head angles
Vibrations
++ ++ ++ + +++ Oversized bushing
A gap between bushing and workpiece
+ + Bushing undersize
Loss of coolant pressure
++ + ++ +++ +++ ++++++ ++ + ++ + ++ + + ++ +++++++ + +++ ++ ++++++ High coolant pressure USER GUIDE
Overheating coolant
++ +++ + ++ ++ Insufficent coolant
Head inside angle excessive wear
309 Head outside angle excessive wear
Too short carbide head
Tool heal drag
Worn supporting pads

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