308A Study Guide 2026
Everything you need to pass the 308A exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
308A exam key facts
- The Red Seal Sheet Metal Worker exam (Ontario 308A) has 120 multiple-choice questions, each with four options and one correct answer. Source
- Candidates for the Sheet Metal Worker 308A certifying exam in Ontario get up to four hours to write it. Source
- The pass mark for the Sheet Metal Worker 308A Red Seal certifying exam in Ontario is 70%. Source
- The Sheet Metal Worker 308A certifying exam costs CA$150 plus HST, paid through the Skilled Trades Ontario Portal. Ontario apprentices with completed training agreements do not pay for their first attempt. Source
- Candidates who fail the Sheet Metal Worker 308A exam must wait 30 days and pay the exam fee again before rescheduling. Source
- After finishing an Ontario Sheet Metal Worker apprenticeship, apprentices get a Provisional Certificate of Qualification valid for one year to pass the 308A exam. Source
📋 308A Exam Format at a Glance
📚 308A Topics to Study (38)
✍️ Sample 308A Questions & Answers
1. What is the purpose of a 'flexible connector' between the air handling unit and the ductwork?
Flexible connectors (typically fabric or rubber) isolate mechanical vibration from the AHU fans, preventing it from transmitting through the rigid ductwork. They also accommodate thermal expansion.
2. What is the standard third-angle projection used in Canadian and North American drawings?
Third-angle projection places the top view above the front view, the right side view to the right of the front view, and the left side view to the left. Each view shows the object as seen from that direction.
3. What happens to accuracy if too few division points are used when developing a curved surface pattern?
Fewer division points mean the curved surface is approximated with fewer straight-line segments, resulting in visible flat spots. More divisions improve accuracy but increase layout complexity.
4. What is the advantage of using self-drilling screws (Tek screws) for sheet metal assembly?
Self-drilling (Tek) screws have a drill-point tip that pierces and drills through the sheet metal, then the threads tap into the hole — all in one operation. This eliminates the need for pre-drilling.
5. What is the purpose of a 'heat sink' when welding thin sheet metal?
Heat sinks (copper bars, aluminum blocks, or wet rags) placed near or behind the weld joint absorb excess heat, reducing the risk of burn-through and minimizing warping on thin sheet metal.
6. What is the purpose of 'tacking' before welding a sheet metal joint?
Tack welds are small spot welds placed at intervals along the joint to hold the pieces in correct alignment and prevent distortion during the full welding process. They become part of the final weld.
🎯 Free 308A Practice Tests
📖 308A Guides & Articles
What Practice Test Geeks adds beyond an AI chat for 308A
An AI chatbot can quiz you, but it can't reproduce the exam conditions or keep your record. Here you get:
- A timed, full-length 308A mock exam — 120 questions in 180 minutes with a 70% pass mark, modeled on the official exam's question count and time limit, followed by a score report broken down by exam domain.
- A fixed 308A question bank: the same test every attempt, so your score is comparable from one try to the next instead of changing with every regenerated quiz.
- Progress saved on your device: completed tests, scores and missed questions stay in My Progress, so you can retake only what you got wrong.
- A printable 308A cheat sheet you can print or save as a PDF.
- 308A flashcards built from the same question bank.
- Free 308A practice tests with the correct answer shown after each question.
How this page was made: written with AI tools and published by Nathan Beja, founder of Practice Test Geeks, who is responsible for its content. Exam facts are checked against the official sources listed below. Not reviewed by a subject-matter expert. Editorial policy
Sources & references
Exam facts on this page (fees, format, dates, passing scores) are checked against these official sources; the date is our last check. Editorial policy
- skilledtradesontario.ca — Renewal, retake fee, score validity, test delivery, fees, retake policy, passing score, score release, time limit · verified Oct 2026
- red-seal.ca — Exam format · verified Oct 2026