What is the difference between G81 and G83?

G81 is a simple drilling cycle that plunges straight to depth and retracts once. G83 is a peck-drilling cycle that drills in increments, fully retracting between pecks to clear chips and re-introduce coolant. Use G83 for deep holes, gummy materials, or any hole deeper than about three diameters.

What does the Q value control in G83?

Q is the peck increment, the depth the drill advances on each plunge before retracting to clear chips. A smaller Q breaks chips more often and is safer in deep or sticky holes, while a larger Q drills faster but risks packing chips. A common starting point is about half the drill diameter.

Why does the cycle only show full words on the first hole?

Canned cycles are modal, meaning the controller keeps drilling with the same Z, R, F, and Q values once they are set. Every hole after the first only needs new X and Y coordinates, and the cycle stays active until a G80 cancels it. This is normal and keeps the program compact.

What is the R retract plane?

R is the clearance height the drill rapids down to and retracts back to between holes. It should sit a few millimetres above the part and clear any clamps or fixtures. Setting R too low risks a crash, while setting it too high wastes cycle time on long rapids.

Is the output metric or inch?

The generated block uses G21 for metric and G54 as the work offset by default. If you machine in inches, change G21 to G20, and swap G54 for your actual work-offset register. Always confirm the units and offset match your setup before running.

G-Code Drilling Cycle Calculator

Hand-coding drilling cycles is repetitive and error-prone, especially across a grid of holes. This tool builds a complete G81 or G83 canned-cycle block from your depth, feed, speed, and a list of hole coordinates, emitting a program you can paste directly into the controller.

How it works

A canned cycle sets the drilling parameters once on the first hole, then repeats for every subsequent X and Y position because the cycle is modal. The generated block follows the standard Fanuc-style structure:

G90 G54 G17 G21
S<rpm> M03
G00 X<first> Y<first>
G00 Z<retract>
G98 G83 X.. Y.. Z<depth> R<retract> Q<peck> F<feed>
X.. Y..        (remaining holes)
G80
M05

For G81 the Q peck word is dropped and the drill plunges straight to depth. G98 returns the tool to the initial Z between holes, and G80 cancels the cycle at the end so following moves behave normally.

How it works in practice and notes

The tool validates that your retract plane sits above the final depth and that feed, speed, and peck values are positive, so a malformed cycle is caught before it reaches the machine. Holes are read one per line as x, y pairs, separated by a comma or space. Always dry-run or single-block the program first, confirm the retract plane clears every clamp, and adjust feeds and speeds to the drill and material before committing to a full run.