Siemens SINUMERIK 840D Programming Manual page 314

4 4
Turning Cycles 03.96
09.01
4.7 Thread cutting – CYCLE97
_VRT (variable retraction path)
With SW 6 and higher, the retraction path can be
programmed on the basis of the initial thread diameter
in parameter _VRT.
When _VRT = 0 (parameter not programmed), the
retraction path is 1mm. The retraction path is always
measured in the programmed system of units inch or
metric.
Further notes
Difference between a longitudinal thread and a
X X
face thread
The cycle automatically calculates whether a
longitudinal or face thread is to be machined. This
Angle < 45°
Angle > 45°
depends on the angle of the taper on which the
thread is to be machined. If the angle at the taper
≤45 degrees, the longitudinal axis thread is
machined, otherwise it will be the face thread.
Z Z
Longitudinal thread Transverse thread
© Siemens AG, 2002. All rights reserved
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SINUMERIK 840D/840Di/810D Programming Guide Cycles (PGZ) – 11.02 Edition