Sandvik Coromant Threading - Manual (Page 78)

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4. Troubleshooting – Thread turning
Abnormal fl ank wear
Vibration
Poor surface on one
fl ank of thread.
• Incorrect method for fl ank infeed
• Insert inclination angle does not
agree with the lead angle of the
thread
• Incorrect workpiece clamping
• Incorrect tool set-up
• Incorrect cutting data
• Incorrect centre height
• Change method of fl ank infeed for F-
and A-geometry to 3 - 5° from fl ank.
For C-geometry to 1° from fl ank
• Change shim to obtain correct angle
of inclination
• Use soft jaws
• Optimize centre hole and check
pressure of face driver
Minimize overhang of tool
Check that the clamping sleeve for
bars is not worn
Use 4C anti-vibration bars
• Increase cutting speed; if this does
not help, lower the speed dramati-
cally. Try F-geometry
• Adjust to correct centre height
• Use solid carbide shanks
Problem Cause Solution