CNC program example code for the G71 Bolt Hole Arc command.
G71 bolt hole arc command makes it easy to drill/tap/bore evenly spaced holes in an arc.
Canned cycles G73, G74, G76, G77, or G81-G89 can be used with G71 bolt hole arc G-code.
G71 Bolt Hole Arc Format
G71 I J K L
I – Radius of the bolt hole arc
J – Starting angle of first hole ( 0 to 360° CCW from horizontal at the 3 o’clock position).
K – Angular spacing between holes (+ or -)
L – Number of evenly spaced holes around bolt hole arc.
Read full article G71 Bolt Hole Arc – CNC Mill Programming
G71 Bolt Hole Arc Programming Example

G71 Bolt Hole Arc Example Program
O005 N10 T2 M06 N20 G90 G54 G00 X2. Y-1.5 N30 S1451 M03 N40 G43 H02 Z1. M08 N50 G81 G99 Z-0.45 R0.1 F8. L0 N60 G71 I1.0 J15. K30. L7 N70 G80 G00 Z1. M09 N80 G53 G49 Z0. M05 N90 M30
CNC program example code for the G71 Bolt Hole Arc command. G71 bolt hole arc command makes it easy to drill/tap/bore evenly spaced holes in an arc.