Millwright screening questions: apprenticeship, alignment, rigging, lockout and machine installs

Millwright screening questions should confirm the candidate's level and training (apprentice year or journeyworker, union or open shop, plant maintenance or construction), then test the precision mechanical work that defines the trade: shaft alignment, bearings and couplings, precision measurement, and rigging and setting equipment. Safety habits around stored energy belong in the same call, because millwrights work inside machines that can start, fall or release pressure. A candidate who says "I do everything" should be able to explain a laser alignment as clearly as a conveyor rebuild.

This page covers construction millwrights who install new equipment and industrial millwrights who maintain it. For broader plant roles with electrical and controls work, use maintenance technician screening questions; for the crane side of heavy lifts, crane operator screening questions.

Which millwright

Apprenticeship and credentials

Many millwrights train through a registered apprenticeship, which the Department of Labor describes as paid work with structured on-the-job learning, a mentor, supplemental classroom instruction and a portable, nationally recognized credential, approved by the Department of Labor or a State Apprenticeship Agency (Apprenticeship.gov). Program length and hours are set in each sponsor's registered standards, so ask the candidate which program, where, and when they completed it. For registered programs, the Verify My Apprenticeship tool lets an employer verify completion with the person's apprentice number and date of birth.

Millwright credentials usually come from apprenticeship and from employer or site qualifications, such as rigging, welding or equipment-specific training, rather than a state trade license. We did not check every state, and tasks such as electrical work, boiler work or operating a crane can carry their own license or certification, so ask the client which credentials the site requires.

Knockout questions

Alignment and precision questions

1. "Talk me through aligning a motor to a pump."
   • Strong answer: locks out, checks and corrects soft foot first, rough aligns, then uses reverse dial, rim and face or a laser system, works to the tolerances from the manufacturer or the plant's standard, accounts for thermal growth where specified, moves the motor in a planned sequence, and records as-found and as-left readings.
   • Red flags: "I straightedge it and it's fine."
2. "What is soft foot, and how do you find it?"
   • Strong answer: a foot that does not sit flat, so tightening it distorts the frame; found with feeler gauges or indicators as each bolt is loosened, corrected with shims, not by forcing it down.
   • Red flags: has never heard of it.
3. "How do you install a bearing on a shaft?"
   • Strong answer: cleanliness, checks shaft and housing fits, uses an induction heater or proper press tools, never hammers on the rolling elements, sets internal clearance on tapered bearings to the specification, correct lubricant and amount.
   • Red flags: heats bearings with a torch.
4. "How do you set and level a new machine on a baseplate?"
   • Strong answer: elevations and centerlines from the drawings, precision levels, jack bolts and shims, anchor bolts, grout preparation and curing, rechecking after grout.
   • Red flags: levels it with a torpedo level.
5. "Which measurement tools do you use every week?"
   • Strong answer: micrometers, calipers, dial indicators, feeler gauges, precision levels, sometimes a laser system; and how they check a micrometer against a standard.
   • Red flags: tape measure only.

Rigging and moving equipment

On construction sites, when workers are in the fall zone hooking, unhooking or guiding a crane load, OSHA requires a qualified rigger under 29 CFR 1926.1425; ask whether the candidate has been designated a qualified rigger and by whom.

Lockout and stored energy

OSHA's general industry standard for the control of hazardous energy, 29 CFR 1910.147, requires employers to train each authorized employee to recognize hazardous energy sources and the means to isolate and control them, and requires the authorized employee to verify isolation and deenergization before starting work (as of October 2026). Ask:

• "Walk me through locking out a conveyor before you change a bearing." Strong: follows the machine-specific procedure, notifies affected people, shuts down, isolates every energy source, applies their own lock and tag, releases stored energy (tension, gravity, pneumatic or hydraulic pressure), tries to start it to verify, then works.
• "What stored energy do people forget?" Strong: spring tension, raised parts that can fall, accumulators, trapped air or hydraulic pressure, rotating flywheels, gravity on conveyors.
• "Someone asks you to 'just clear a jam' without locking out. What do you say?" Strong: no, and explains why, then does it properly. Red flag: describes doing it regularly.

Troubleshooting and fabrication

• "A pump keeps failing its mechanical seal. How do you find out why?" Strong: looks at alignment, pipe strain, bearing condition, operating point and running dry, seal flush, installation practice; does not just replace the seal again.
• "How do you use vibration or other condition monitoring data?" Strong: reads trends or works with the reliability tech, knows common signs of misalignment, imbalance and bearing wear, and plans repairs into shutdowns.
• "What welding, cutting and fabrication do you do?" Strong: names processes, positions and what they built (guards, brackets, supports), and whether they hold any welding qualification; see welder screening questions for depth.
• "Hydraulics and pneumatics?" Strong: reads basic schematics, replaces pumps, cylinders and valves, bleeds and tests systems, relieves pressure first.

How millwright experience gets overstated

• Parts replacement called alignment. Ask for the tolerances they worked to and how they recorded readings.
• Laser alignment from watching a contractor. Ask which system they used themselves.
• Construction-only millwrights for breakdown maintenance roles, or the reverse. Ask about the last breakdown they fixed under production pressure, or the last machine they set from new.
• Helper time counted as journeyworker time. Ask when they completed the apprenticeship.

Scoring

In the submittal, list the equipment by type and size, alignment methods and systems used, rigging experience, welding qualifications (processes, positions, the employer that qualified them), and the candidate's own account of their motor-to-pump alignment. Do not ask about past injuries or workers' compensation claims; ask whether the candidate can meet the job's physical requirements, with or without accommodation.