Siemens Sinumerik 840D sl Programming Manual page 220

Motion commands
10.10 Thread cutting
The face thread is described by:
● Thread diameter (preferably in the X direction)
● Thread lead (preferably with I)
Tapered thread
The tapered thread is described by:
● End point in the longitudinal and transverse direction (taper contour)
● Thread lead
The taper contour is entered in Cartesian coordinates X, Y, Z in absolute or incremental
dimensions - preferentially in the X and Z direction for machining on turning machines.
Allowance must also be made for the run-in and run-out paths, across which the feed is
accelerated or decelerated.
The specification of the lead depends on the taper angle (angle between the longitudinal axis
and the outside of the taper):
220
Programming Manual, 01/2015, 6FC5398-1BP40-5BA2
Fundamentals