Page 311 - ISCAR(HOLE_MAKING_CATALOG_65)

USER GUIDE
GUNDRILLS

Gundrill Troubleshooting Guide
Possible Causes

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 edge Interrupted chip flow Too small flute clearance Incorrect drill profile Incorrect head angl

Hole Problems
Oversize + + + + + + + + + + + + + + + + +
Undersize + + + + + + + + +
Rough surface finish + + + + + + + + + + + + + + + + + + + + + +
Runout + + + + + + + + + + + + + + + + + + + + + + + +
Conical entrance + + + + + +
Curved hole axis + + + + + + + + + + + + + + + + + + +

Drill Problems
Breakage + + + + + + + + + + + + + + + + + + + + + + + + + +
Chipping + + + + + + + + +
Poor drill life + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Excessive margin wear + + + + + + + + + + + + +
Excessive corner wear + + + + + + + + + + + + + +
Excessive flank wear + + + + + + + + + + + + + +
Drill heat + + + + + + + + + + + +
Flute bending + + + + + + + + + + + + + + + +
Damaged wear pad + + + + + + + + + + + + + + + + + +
Built-up edge + + + + + + + + + + + + + + +
Cratering + + + + + + + + + + + + +

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