Hiring guide · CNC machinists
How to test a CNC machinist before hiring
Test a CNC machinist before hiring by giving every applicant the same set of real shop scenarios — setup and prove-out, program edits at the control, print reading and GD&T, troubleshooting — administered on-site so the answers are their own, and scored against documented criteria so applicants can be compared directly. Resumes and interviews no longer separate strong machinists from rehearsed ones; demonstrated skill does.
Why resumes and interviews stopped working
Applicants now use AI to tailor resumes to a posting word for word and to rehearse interview answers. A shop owner reading applications sees identical claims from the strongest and weakest candidates. The only signal left is what the applicant can actually do — which is why shops increasingly test before the offer instead of discovering the truth in the first two weeks on a machine.
Step 1: name the failure points
Start from how a bad hire actually fails in your shop: crashed setups, edits made at the control without understanding the cycle, misread prints, scrap that never gets a root cause. Those failure points — not a generic skills list — define what the test must measure. A useful assessment is built from your posting and your work, because a machinist test written for another shop measures another shop's risks.
Step 2: use real scenarios, not trivia
Multiple-choice trivia measures memorization. Scenario questions measure judgment: how do you prove out a new program without wrecking anything; a threaded part comes back with the pitch diameter shallow — what do you change in the cycle and how do you restart; walk through picking up a rework part that a previous fix already touched. Strong machinists answer these in the vocabulary of the machines they have run; pretenders generalize.
Step 3: administer on-site
Take-home and remote tests are now answered by AI as often as by applicants. On-site administration during the hiring visit means the answers are genuinely the applicant's own — and it costs the applicant nothing extra, because they are already standing in your shop.
Step 4: score every applicant the same way
Define the scoring criteria per question before anyone takes the test, score each answer against those criteria, and document the result. Consistent, documented, job-related scoring is what makes results comparable across applicants — and it is the posture the EEOC's Uniform Guidelines on Employee Selection Procedures expect from any selection test: job-related, consistently administered, and defensible.
Common questions
Is it legal to give applicants a skills test?
Pre-employment skills testing is legal and widely used in the United States. The operative standard, from Title VII case law and the EEOC's Uniform Guidelines (UGESP), is that a test should be job-related and consistent with business necessity, administered the same way for every applicant. A documented, job-related assessment is generally easier to stand behind than undocumented gut-feel interviews. For your specific situation, consult employment counsel.
What should a CNC machinist test cover?
The skills your opening actually requires — typically setup and prove-out, program edits at the control, print reading and GD&T, in-process inspection, and troubleshooting to root cause. The right mix depends on your machines and work, which is why assessments built from the specific job posting outperform generic test banks.
Written scenarios or a hands-on tryout?
They answer different questions and pair well. A scenario assessment tells you cheaply, before the offer, who is worth a paid tryout; the tryout then confirms hands-on execution. Shops that only use tryouts spend a supervised shift finding out what a scenario assessment would have shown in under an hour.
How long should the test be?
Long enough to cover the role's real failure points and short enough that serious applicants finish it during a hiring visit. Length should be custom to the role — a founding machinist role for 5-axis work warrants more depth than a production operator opening.
See it on your own opening
See how this works for machine shops, try the 2-minute demo, or take one of the two paths below.