HEIDENHAIN MANUALplus 620 65
2.4 Units—Centric Drilling
"Centric tapping" unit
The unit cuts axial threads using stationary tools.
Unit name: G73_ZENTR / Cycle: G73 (see page 296)
Retraction length L: Use this parameter for floating tap holders. The
cycle calculates a new nominal pitch on the basis of the thread depth,
the programmed pitch, and the “retract length.” The nominal pitch is
somewhat smaller than the pitch of the tap. During tapping, the tap is
pulled away from the chuck by the retraction length. With this method
you can achieve higher service life from the taps.
Access to the technology database:
Machining operation: Tapping
Affected parameter: S
Pattern form
APP Approach: see page 51
DEP Departure: see page 51
Cycle form
Z1 Start point drill (starting point of hole)
Z2 End point drill (end point of hole)
F1 Thread pitch
B Run-in length
L Retraction length when using floating tap holders
(default: 0)
SR Return speed (default: Tapping speed)
Further forms: see page 46