Dear Fellow Machinist,

Picture this. A new programmer, six months into the job, staring at a print with a pattern of deep holes in 4140 steel. He knows he needs to drill them. He knows there's a canned cycle for that. What he doesn't know is that three different drilling cycles are sitting right next to each other in that manual — and picking the wrong one isn't a "small mistake" kind of wrong. It's a broken-drill, scrapped-part, explain-it-to-the-boss kind of wrong.

So what does he do? He picks the one he's seen used the most. Not the one that's right for the job. The one that's familiar.

That's not programming. That's guessing with extra steps.

And here's the truth nobody bothers to tell you when you're starting out:

Today we're taking 3 cycles that most shops use constantly — G73, G83, and G84 — and pulling them apart until you know exactly when to reach for each one, and exactly why they are not interchangeable.

Let's get into it.

Every single peck retracts fully to the R plane. Not partway. Not "close enough." All the way, every time. That's not a side effect — that's the entire reason this cycle exists.

Deep holes need the chip gone, not just interrupted. A full retract clears the chip completely and gives coolant a clean shot straight down the hole before the next peck begins.

Heat has a moment to dissipate between pecks. It's forgiving on shops running marginal coolant. On a vertical mill, gravity does half the chip-clearing work for you.

The tradeoff is time. Every full retract costs you a beat. Which is exactly why G73 exists — and exactly why people mix the two up.