*indicates optionalG74 End Face Grooving Cycle Peck Drilling:  Rapid,  Feed,  Programmed Path, [S] Start position, [P] Peck retraction (Setting 22).
The G74 canned cycle is used for grooving on the face of a part, peck drilling, or turning.
***Warning: The D code command is rarely used and should only be used if the wall on the outside of the groove does not exist like the figure above. The D code can be used in grooving and turning to provide a tool clearance shift, in the X axis, before returning in the Z axis to the C clearance point. But, if both sides to the groove exist during the shift, then the groove tool would break. So you wouldn t want to use the D command.
A minimum of two pecking cycles occur, if an X, or U, code is added to a G74 block and X is not the current position. One at the current location and then at the X location. The I code is the incremental distance between X-Axis pecking cycles. Adding an I performs multiple pecking cycles between the starting position S and X. If the distance between S and X is not evenly divisible by I then the last interval is less than I.
When K is added to a G74 block, pecking is performed at each interval specified by K, the peck is a rapid move opposite the direction of feed with a distance defined by Setting 22. The D code can be used for grooving and turning to provide material clearance when returning to starting plane S.G74 End Face Grooving Cycle:  Rapid,  Feed,  Groove.