Fanuc G85 Boring Cycle – CNC Mill Programming

Fanuc G85 Boring Cycle is also called Fanuc G85 Reaming Cycle.
As Fanuc G85 boring cycle can be used for Reaming operation.

Fanuc G85 Boring Cycle – Reaming Cycle

Tool traverses down to end depth with feed and retracts the withdrawal plane with feed.

Fanuc G85 Boring Cycle Format

G85 X Y Z R F K

X Y – Hole position
Z – Boring depth (Absolute).
R – Tool starting position above the hole.
F – Cutting feed rate
K – Number of repeats (if required)

Fanuc G85 Boring Cycle

Fanuc G85 Boring Cycle

Fanuc G85 Boring Cycle Operation

1 – After positioning along X and Y axis, rapid traverse is performed to point R.
2 – Boring/Reaming is performed from point R to end-depth-point Z with specified feed F.
3 – After completing depth Z with feed F, Tool returns with the same feed F.

Return plane is dependant on G98, G99 G-codes.
If G98 is specified with G85 boring cycle the tool returns to Initial-level.
If G99 is specified then tool will return to R level.

Fanuc G85 Boring Cycle Example Program

M3 S100
G90 G99 G85 X300. Y–250. Z–150. R–120. F120.
Y–550.
Y–750.
X1000.
Y–550.
G98 Y–750.
G80 G28 G91 X0 Y0 Z0
M5