Free: 50-Question 420B Mock Exam PDF

What's inside

• 50 original exam-style questions drawn from the seven topic areas in our 420B Ironworker (Generalist) bank — Structural Steel Erection, Rigging & Hoisting, Welding & Cutting, Blueprint Reading & Layout, Reinforcing Steel, Safety & Fall Protection, and Tools & Equipment
• Every answer explained in the back of the PDF, so a wrong answer turns into something learned, not just a lost mark
• Works offline — study in the lunchroom, the truck, or anywhere without a signal. No account needed.

The seven topic areas, and where ironworkers drop marks

The 50 questions in the free PDF come from the same pool as our full 121-question 420B bank. Here is how that bank splits, what each area asks about, and the mistakes we see repeated.

• Structural Steel Erection — 24 questions The largest area and the closest to the day job: connection sequence, temporary bracing and guying, plumbing up, column splices, deck installation. Much of it is bolting — snug-tight versus fully pretensioned, turn-of-nut, direct-tension-indicator washers. Marks go two ways: answering sequence questions from habit rather than from the stability of an incomplete frame, and not being able to say which joints must be slip-critical.
• Rigging & Hoisting — 23 questions Sling angle and the tension it multiplies, working load limits, vertical versus choker versus basket hitches, wire rope and synthetic sling removal-from-service criteria, shackles, spreader beams, tag lines, hand signals and crane load charts. The reliable killer is the sling-angle calculation: load per leg is not the total divided by the number of legs, and the angle that matters is measured from horizontal.
• Welding & Cutting — 18 questions Field processes — SMAW and FCAW — with electrode selection and storage, preheat, fit-up, and the usual discontinuities (undercut, porosity, lack of fusion) traced back to their causes, plus oxy-fuel and air-arc cutting and hot-work precautions. The recurring miss is the weld symbol: which side of the joint the arrow refers to, and what the field-weld flag and all-around circle change.
• Blueprint Reading & Layout — 15 questions Erection drawings, piece marks and shipping lists, grid lines and elevations, detail views, camber, and the layout that follows — offsets, 3-4-5, transferring elevations, checking a bay for square and plumb. Apprentices who read the same drawings daily still stumble on revision clouds and on switching units mid-question.
• Reinforcing Steel — 18 questions Bar sizes and mill markings, bar lists and placing drawings, lap splices and development length, concrete cover, hooks and bends, tying patterns, chairs and bolsters, mechanical couplers. Two habits cost marks: holding cover in your head as one number rather than a value that changes with exposure and member type, and treating lap length and development length as the same thing.
• Safety & Fall Protection — 14 questions Fall restraint versus fall arrest, anchorage ratings, connectors, lanyards and self-retracting devices, controlled access zones, safety nets, ladders and scaffolds, PPE, lockout. Clearance calculation is where it goes wrong: free fall is only part of it, and deceleration distance, harness stretch and the distance from the D-ring to your boots get left out.
• Tools & Equipment — 9 questions Spud wrenches, bull pins and connecting bars, impact wrenches and torque verification, powder-actuated tools, grinders and cutting gear, inspection and maintenance. The smallest area and the most often skipped, which is a shame — torque-wrench calibration and powder-actuated tool certification are pure recall.

Writing the 50-question mock the way it is meant to be written

Used as a quiz, a mock tells you little. Used as a diagnostic it tells you what to study next week. In this order:

• One timed pass, no book, no phone The Red Seal exam for this trade runs 120 questions in a four-hour writing time — about two minutes each. Give yourself 100 minutes for the 50 and hold to it. Rigging and clearance calculations are what eat the clock, so find out now whether you can do them at pace.
• Put a dot beside every answer you guessed As you go, not afterwards. A guess that came back right is a gap you will otherwise never see.
• Score it, then sort the misses into two piles Calculation misses — sling tension, fall clearance, lap lengths, layout dimensions — get worked on paper until the method is automatic. Recall misses — bolt types, sling rejection criteria, weld symbols, cover — get short daily sessions. Mixing the two is why studying feels busy and changes nothing.
• Study only the misses and the dots Read the explanation in the back of the PDF, then go to the source: the occupational standard, your rigging handbook, the job drawings. Re-sitting the same 50 a week later measures your memory of the paper.

How this lines up with the Red Seal exam for Ironworker (Generalist)

The Red Seal Program publishes an exam breakdown for every trade. For Ironworker (Generalist) it lists 120 questions across seven blocks: Occupational skills (15), Rigging and hoisting (22), Cranes (11), Reinforcing (19), Pre-stressed and post-tensioned concrete (8), Erection, assembly and installation (34), and Maintenance and upgrading (11) (red-seal.ca exam information). Its Exam Preparation Guide states the questions are multiple choice with four options and one correct answer, the pass mark is 70% and the writing time is four hours.

These figures are current as of August 2026. Red Seal has published a new occupational standard for this trade and exams built on it are under development, so the question count and the weightings will change once those exams come into use. Check the trade page at red-seal.ca before you book.

Our topic names are our own and do not map one-to-one. Erection is the heaviest on both lists; crane content sits inside our Rigging & Hoisting area, and welding and blueprint questions fall under the official occupational-skills and erection blocks. We have no pre-stressed and post-tensioned set, so fill that gap from the occupational standard. Your provincial or territorial apprenticeship authority administers the exam and is the authority on eligibility, scheduling and what you may bring in.

Want every question?

This mock exam is a 50-question slice. The 420B Complete Question Bank has all 121 questions with a full explanation for every answer, organized by the published occupational standard topic areas, in one printable offline PDF.

Questions ironworkers ask us

• I only do structural work. Are the rebar questions worth my time? Yes. Reinforcing sits inside the Generalist scope, and the exam is written to the national scope of the trade, not to whatever your company is contracted for. Cover, lap length and placing drawings are what most structural hands have not touched since school.
• Does the free PDF include crane and post-tensioning questions? Crane material is in there, folded into the rigging questions — load charts, setup, signals, lift planning — rather than in its own section. There is no pre-stressed or post-tensioned set.
• Metric or imperial? Both, deliberately. Drawings, bar sizes and rigging hardware come at you in a mix, and converting under time pressure is its own skill. If a conversion slows you here, that is a finding, not a misprint.
• How is this different from the online 420B quiz? The PDF is one timed sitting with explanations held back until the answer key. The quiz marks each question as you answer it — better for learning a topic, worse for rehearsing exam day.