Based on the Red Seal Industrial Mechanic (Millwright) standard & official exam weighting
About the certification
In Ontario, Industrial Mechanic (Millwright) is trade code 433A. The written Certificate of Qualification (C of Q) exam is administered by Skilled Trades Ontario. 433A is a Red Seal trade, so Ontario's certifying exam is the interprovincial Red Seal Industrial Mechanic (Millwright) exam — passing it earns both your C of Q and the Red Seal endorsement.
The Red Seal exam has 135 multiple-choice questions with a 70% pass mark, and candidates are generally allotted up to about four hours. Questions are built from the Red Seal Occupational Standard for the trade, which covers rigging and hoisting, mechanical power transmission, material handling and process equipment, fluid power systems, and preventative and predictive maintenance.
ExamHub's free 433A practice quiz has 260 original questions across six topic areas that mirror the official exam weighting, with an explanation and a cited source for every answer. It is unofficial study practice — always confirm current requirements with Skilled Trades Ontario and the current Red Seal Occupational Standard.
What's covered
Categories map to the Red Seal exam's Major Work Activity blocks, with mechanical power transmission the most heavily weighted — just as it is on the real exam.
Try a few
Five questions pulled from the full bank, with the answer shown — use the quiz above for the real timed experience.
Why: Atmospheric testing comes first: oxygen content, then flammable gas, then toxic contaminants. Confined-space entry is part of a written permit, with an attendant stationed outside and rescue arranged before anyone enters.
Why: Sling capacity at an angle is the vertical rating multiplied by the sine of the angle from horizontal: 4,000 lb × sin(60°) = 4,000 × 0.866 ≈ 3,460 lb — noticeably less than the vertical rating even at a fairly steep 60° angle.
Why: Belt-drive speed is inversely proportional to pulley diameter: driven speed = driver speed × (driver diameter ÷ driven diameter) = 1,750 × (4 ÷ 7) ≈ 1,000 rpm — the larger pulley turns slower.
Why: When the net positive suction head available (NPSHa) falls below what the pump requires (NPSHr), local pressure inside the pump can drop below the fluid's vapour pressure, causing vapour bubbles to form and then violently collapse against internal surfaces.
Why: By Pascal's law, pressure is equal throughout: pressure = 100 lbf ÷ 2 in² = 50 psi. Output force = 50 psi × 20 in² = 1,000 lbf — a 10:1 force multiplication matching the 10:1 area ratio.
FAQ
The interprovincial Red Seal Industrial Mechanic (Millwright) exam has 135 multiple-choice questions, confirmed directly on red-seal.ca. ExamHub's practice bank has 260 original questions, and the timed 'Test Me' mode draws a 135-question practice test to match.
The Red Seal pass mark is 70%. On the real 135-question exam that's 95 correct answers; ExamHub uses the same 70% threshold.
Red Seal exams are generally allotted up to about 4 hours. ExamHub's Test Me mode gives you up to 4 hours as well, which is far more than most people need.
The Red Seal exam weighting is split across six Major Work Activity blocks: common occupational skills, rigging/hoisting/moving, mechanical power transmission (the largest block), material handling and process systems, fluid power systems, and preventative/predictive maintenance and commissioning.
No. These are original questions written by ExamHub from the Red Seal Occupational Standard, Skilled Trades Ontario's trade information for Industrial Mechanic Millwright (433A), and CCOHS safety guidance. They cover the same topics but aren't copies of any real exam. Always verify against current regulations before relying on any value in the field.