CNC program example for cnc vertical machining centers illustrates the use of G81 drilling cycle.
CNC milling machine controls like Fanuc, Haas etc, has many standard canned cycles built-in the cnc control, these canned cycles make the cnc programmer/ setter/ operator’s life easier as canned cycles are easy to program and debug.
Sample Program

G81 Drilling Canned Cycle CNC Milling Program Example Code
O10075 N1 T16 M06 N2 G90 G54 G00 X0.5 Y-0.5 N3 S1450 M03 N4 G43 H16 Z1. M08 N5 G81 G99 Z-0.375 R0.1 F9. N6 X1.5 N7 Y-1.5 N8 X0.5 N9 G80 G00 Z1. M09 N10 G53 G49 Z0. M05 N11 M30
Explanation
O10075 Program number (there are many programs in cnc memory so they are distinguished by their number).
N1- Tool change (M06) to tool no.16
N2- Tool rapidly moves (G00) to first drilling position X0.5 Y-0.5 while taking into account Zero-offset-no. 1 (G54)
N3- Drill starts rotating clockwise (M03) with 1450 rpm (S1450).
N4- Drill takes depth Z1. taking into account tool length compensation (G43 H16), coolant is turned on (M08).
N5- Drilling cycle (G81) parameters, drill depth (Z) and cutting feed (F) are given, with this command first drill is made at current position (X0.5 Y-0.5).
N6- As drilling cycle continues it’s work with every axis movement so next drill is done at X1.5
N7- Third drilling hole at Y-1.5
N8- Fourth drill at X0.5
N9- Drilling cycle is canceled (G80), Coolant is turned off (M09).
N10- Taking Machine-coordinate-system (G53) into account the drill is taken to Z0 position. Tool length compensation is canceled (G49), cutter rotation is stopped (M05).
N11- CNC part-program is ended.
G & M Codes
Code | Description |
---|---|
T | Tool no. used. |
M06 | Tool change command. |
G90 | Absolute programming |
G54 | Zero offset no.1 |
G00 | Rapid traverse |
S | Cutter speed |
M03 | Cutter rotation Clockwise |
G43 | Tool length compensation. |
M08 | Coolant on. |
G81 | Fanuc drilling cycle. |
F | Cutting feed. |
G80 | Canned cycle cancel. |
M09 | Coolant off. |
G53 | Machine coordinate system selection. |
G49 | Tool length compensation cancel. |
M05 | Cutter rotation stop. |
M30 | CNC part-program end. |