Sandvik Coromant Threading - Manual (Page 80)

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4. Troubleshooting – Thread turning
Excessive edge pressure
• Work hardening material in combina-
tion with infeed depths which are
too shallow
• Excessive pressure on cutting edge
• Insert thread profi le angle too small
• Reduce the number of infeeds
• Change to F-geometry
• Change to a tougher grade
• Use modifi ed fl ank infeed
Incorrect thread profi le
• Unsuitable thread profi le (angle of
thread and nose radius) external
inserts used for internal operation
or vice versa
• Wrong centre height
• Holder not 90° to centre line
• Pitch error in machine
• Adjust to correct tool, shim and
insert combination
• Adjust centre height
• Adjust holder to 90°
• Correct the machine
Problem Cause Solution