Page 130 - HOLE MAKING CATALOG p001-148

INDEXABLE DRILLS USER GUIDE

Chip jamming Broken Screw

Rotating drill • Use recommended torque wrench
• Improve chip formation (change chipbreaker • Lubricate the screw before tightening

type or cutting condition) Insufficient machine power-
• Increase coolant pressure
• Reduce speed and feed
Non-rotating drill • Use recommended chipbreaker for low feed
• Improve chip formation (change chipbreaker
Insufficient machine torque
type or cutting condition)
• Increase coolant pressure

Deflection

Rotating drill • Reduce feed
• Use shorter drill overhang (if possible) • Use recommended chipbreaker for low feed
• Reduce feed by 30-50%
• Check that overlapping is correct Chip Formation Problems

between inner and outer inserts Long chip/ Chip jamming:
• Check inner insert is positioned over center within its limits This typical problem with stainless or low carbon steel,
• Increase coolant pressure can affect hole quality, especially on surface finish, and
• Change the insert chipbreaker in some cases can cause insert or tool breakage.
• Stabilize clamping device
Optimal Shape Too Long Too Tight
Non-rotating drill
• Check misalignment
• Check that overlapping is correct

between inner and outer inserts
• Check inner insert is positioned over center within its limits
• Rotate drill 180 degrees
• Increase coolant pressure
• Change the insert chipbreaker

If machining at Increase
high speed, first speed within
reduce speed. recommended
If unsatisfactory, limits. If not
increase feed, but satisfactory,
do not exceed decrease feed.
upper limit.

128 ISCAR