Operation Manual

HEIDENHAIN CNC PILOT 640 297
4.6 Thread and undercut cycles
Examples of thread and undercut cycles
External thread and thread undercut
The machining operation is to be performed in two steps. The thread
undercut DIN 76 produces the undercut and thread chamfer. In the
second step, the thread cycle cuts the thread.
First step
The parameters for the undercut and thread chamfer are programmed
in two superimposed input windows.
Tool data
 Turning tool (for external machining)
 TO = 1 (tool orientation)
 A = 93° (tool angle)
 B = 55° (point angle)
Second step
The thread cycle (longitudinal)—expanded cuts the thread. The
cycle parameters define the thread depth and the proportioning of
cuts.
Tool data
 Threading tool (for external machining)
 TO = 1 (tool orientation)