System information
SECTION FOUR - PREPARATORY FUNCTIONS (G CODES)
Hard tap cycle (G88)
G88 G98/G99 Z____ R____ F____ P____ (Q____ V____)
The G88 command specifies the hard tapping cycle. P(dwell) can be used if the distance between
holes is small to give the spindle time to reverse to its proper direction.
This cycle will do the following.
Note 2: The tap cycle will not stop until the end of the tap cycle even if feedhold or block mode
are applied. If halt is applied the tap reverses and stops when it is out of the hole.
1. Rapids to point R
2. Feeds point Z
3. Reverses the spindle
4. Feeds to point R
5. Reverse the spindle
6. Dwells for P___ seconds
7. Rapids to initial point, if specified by the G98 code
Note 1: If the spindle is running clockwise when the G88 is initiated, right tapping is done.
If the spindle is running counterclockwise when the G88 is initiated, left tapping is done.
Note 3: If Q__ is specified on the G88 block, peck tapping is preformed. The Q__ specifies the
peck increment. The V__ specifies the first depth to tap.
Use F.05
F specifies the lead
Example: ΒΌ - 20 tap
1/20 = .05 lead
Hard tapping is an option supplied by the machine tool builder and should only be used if
the option has been installed.
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