Aug 25, 2026 ● hireCNC
CNC Machinist Interview Questions: What Shops Actually Ask
A while back a question came up in our MACHINIST group: what do you ask to figure out if a machinist really knows their stuff?
Shop owners piled in.
What came back wasn’t what you’d find in an article about interview questions. Almost nobody mentioned “tell me about a time you faced a challenge.” A lot of them didn’t want to ask questions at all — they wanted to hand you a print and point at a machine.
So if you’ve got an interview coming up, this is the real list. Their questions, and what I’d tell you about answering them.
First thing to know: it might not be an interview
This is the part that surprises people.
A lot of shops have stopped trusting conversation entirely. Here’s what shop owners said they do instead:
“Hire them as a 1099, give them a print and a machine. Tools are loaded, offsets aren’t set. Make me a good part.”
“We’ve got a test piece that should take less than an hour. If they can’t make it, you’ve got a button pusher, not a machinist.”
“We run a 1-2 hour manual lathe test — 1-3 fits (+0/-0.002), threads, and basic measuring. You see technique, time, stress management, and honesty right away.”
Read that last one again. He’s not just checking whether the part comes out. He’s watching how you work when somebody’s standing there.
What to do about it. Ask when you schedule the interview whether there’s a hands-on portion, and how long. No good shop will hold that against you — it tells them you’ve done this before. And show up in boots with your own mics and indicators if you have them.
If they do put you on a machine, the thing that gets people isn’t skill. It’s rushing. Take the time to check the part. Nobody has ever failed a shop test for measuring twice.
The quick math
Several owners said they open with mental math, and that a surprising number of people miss it.
- “Tangent of 45?”
- “9 x 7?”
- “Square root of 9?”
- “How many thousandths in an inch? How many per mic thimble turn?”
- “How comfortable are you with a 1 inch mic?”
The answers are 1, 63, 3, a thousand, and twenty-five per turn on a standard inch mic.
One owner added, about the 9 x 7: “You’d be shocked how many blow this one.”
He’s not testing your arithmetic. He’s testing whether you freeze. Say the number. If you get it wrong, say you got it wrong and give the right one — that’s a better look than going quiet.
The mic question is the one to take seriously. Comfortable with a 1-inch mic means: can you feel the right amount of pressure, do you know to check the standard, do you know your own repeatability. If you can answer in that language, you’re already past most applicants.
The process questions
These are the ones where they find out whether you understand the work or just run the program.
“How would you get rid of chatter on a bore?”
They want to hear you go after rigidity first. Shorten the overhang, get a stiffer bar, take the pressure off the tool. Then speeds and feeds — often more feed, not less. Sharper insert, smaller nose radius. Check that the part and the workholding aren’t the thing that’s actually moving.
Say what you’d try first and why. Somebody who lists ten fixes in random order sounds like they’ve read about chatter. Somebody who says “first I’d get the bar as short as I can” sounds like they’ve fixed it.
“How would you add a taper to a turned dimension?”
Say which machine you’re on. On a CNC lathe you program it. On a manual you’ve got the compound, a taper attachment, or offsetting the tailstock — and each one has a reason you’d pick it.
“How do you pick up an edge with an indicator to within .0002?”
At two tenths you’re not using an edge finder. You’re indicating off something known — a pin, a gage, sweeping a bore with a tenths indicator — and you know your indicator’s resolution. If you’d do it a different way, say so. There’s more than one right answer here and they know it.
“Walk me through your order of operations for this print. What tools would you use?”
This is the big one. Some shops hand you an actual print and let you talk.
Don’t jump to the first cut. Start with how you’re holding it, what surface you’re establishing first, where your datums are, what has to be done before the part gets flexible. Say out loud when you’d stop and check something. Say when you’d ask.
They’re not grading the plan. They’re listening to how you think.
The basics they expect you to have
One owner put it bluntly:
“If you can’t tram a mill vise, indicate a 4-jaw, or sharpen a drill — good luck. Those are basic skills.”
If any of those three are rusty, that’s your homework before the interview. They come up constantly, and not knowing one of them ends the conversation early.
Written and CAD/CAM tests
Programming and setup roles get a second layer:
“We’ll hand you a program and ask you to mark up what each section does, then draw the part.”
“SolidWorks? Mastercam? Let’s see you reverse-engineer and program a part. Then estimate setup and cycle time.”
The estimate is the part people forget. Being roughly right on setup and cycle time is what separates somebody who can program from somebody a shop can schedule work around. If you don’t know, give a range and say what would move it.
What they’re really screening for
Two answers came up more than any technical question, and neither is about skill.
“The biggest question? How do they feel about learning? A good machinist never says they’ve learned it all.”
“Ask how they take care of their tools, their station, their machines — this tells you a lot.”
I’d take those seriously. If you’ve got twenty years on Haas and the shop runs Mazak, the thing that gets you hired is how you talk about picking up the new control. Confidence about what you know, plus an honest answer about what you don’t, beats claiming everything.
And when they ask what you’d bring, or how you keep your area — that’s a real question. Answer it like one.
Questions worth asking them
You’re interviewing them too, and most machinists don’t. A few that get you real information:
- What’s the machine list, and what would I be on first?
- Who does the programming — is it at the machine or in an office?
- What does the overtime actually look like in a normal month?
- Is there a written pay progression, or is it case by case?
- Why is this seat open?
That last one tells you more than anything else you’ll ask.
And ask the number in the first conversation. Plenty of shops still won’t put pay in the ad. I’ve got opinions about that, but it’s not your problem to solve. Just ask.
The short version
If you do five things, you’ll interview better than most people who walk in:
- Ask whether there’s a hands-on test, and bring your own tools.
- Don’t rush the test part. Measure it.
- Answer the math fast, and out loud.
- On process questions, say what you’d do first and why.
- Be honest about the gap between what you know and what the job needs.
None of that requires being a better machinist than you already are.
Everything above came from shop owners answering that question in our group. If you want their raw answers, unedited and in their own words, they’re here: Top Interview Questions for CNC Machinist.
Useful reading if you’re about to be interviewed. Also useful if you’re the one doing the interviewing.
hireCNC lists CNC machining jobs across the U.S. and Canada, and runs the MACHINIST group — the largest machinist community on Facebook.
