Fast facts
| Trade code | 456A |
|---|---|
| Sector | Industrial |
| Classification | Voluntary trade |
| Certifying exam | Required (O. Reg. 876/21, s. 3) |
| Apprentice to journeyperson ratio | Not subject to a ratio |
| Red Seal trade | Yes |
| Active apprentices in Ontario | 1,512 (reported in Ontario's apprenticeship dataset) |
| Approved sponsors | 634 |
| Certifying body | Skilled Trades Ontario |
Last verified August 20, 2026 against the sources listed below.
What does a welder do?
A Welder permanently joins pieces of metal or manufactured parts using metal filler and heat and/or pressure; builds structures and repairs broken or cracked parts according to specifications; and carries out special processes, such as welding studs and brazing.
Skilled Trades Ontario describes the work of this trade as follows:
- lays out, cuts, and forms metals to specifications
- fits sub-assemblies and assemblies together and preparing assemblies for welding
- uses three major types of welding: arc, gas, and resistance
- uses various welding and cutting processes to join structural steel and cut metal in vessels, piping and other components
- fabricates parts, tools, machines and equipment
- joins parts being manufactured, builds structures and repairs damaged or worn parts
- controls for quality before, during and after welding
How long is the welder apprenticeship?
The in-school portion of this apprenticeship runs to 3 levels. Skilled Trades Ontario does not publish a total hour requirement for this trade on its trade page; confirm the current requirement in the trade's apprenticeship training standard before signing an agreement.
What do you study in school for the 456A?
The in-school portion covers, but is not limited to:
- applied safety procedures
- reading of blueprints and welding symbols
- material and process quality
- welding theory
- shielded metal arc welding
- gas metal arc welding
- gas tungsten arc welding
- plasma arc welding
- submerged arc welding
- automatic/semi-automatic processes
- fitting/fabrication
- thermal cutting: oxy-fuel-gas, plasma arc, air carbon arc
Is welder a compulsory trade in Ontario?
No. Welder is a prescribed trade under section 1 of O. Reg. 876/21, but it is not on the compulsory list in section 2. That means you can legally work in this trade in Ontario without holding a Certificate of Qualification. Certification is voluntary and serves as formal proof of competency to employers and clients.
Voluntary classification only covers certification under the Building Opportunities in the Skilled Trades Act. Specific work within the trade can still require separate licences or permits under other Ontario statutes, so confirm the rules for the actual work being done. The 23 trades where certification is mandatory are on the compulsory trades list.
How do you become a welder in Ontario?
The apprenticeship pathway for this trade is administered by Skilled Trades Ontario under section 14 of the Building Opportunities in the Skilled Trades Act, 2021:
- Find a sponsor and register a training agreement. An employer or union sponsor takes you on and the training agreement is registered with the ministry.
- Complete the on the job and in school training. The skills are set out in the trade's Apprenticeship Training Standard, signed off by your sponsor as you demonstrate them, alongside levels of in school theory at a training delivery agent.
- Receive your Certificate of Apprenticeship. Skilled Trades Ontario issues it when the program is complete.
- Pass the certifying exam. This trade has a certifying exam under O. Reg. 876/21, s. 3. Passing it earns the Certificate of Qualification, the voluntary proof of qualification for this trade.
The exact training standard, current curriculum and program details are on the Skilled Trades Ontario page for Welder. On the job hour requirements vary by trade and are not published on this page yet; confirm them in the training standard before signing an agreement.
Is the 456A a Red Seal trade?
Yes. Welder participates in the Interprovincial Red Seal Program, the national standard for the trade across Canada, stewarded by the Canadian Council of Directors of Apprenticeship. A Red Seal endorsement on an Ontario Certificate of Qualification means the qualification is recognized in other provinces and territories without re examination, which matters for workers moving between provinces and for employers hiring from outside Ontario.
The Red Seal exam for this trade has 125 multiple-choice questions, each with four possible answers and exactly one correct answer.
How the 125 questions are distributed
| Major Work Activity | Questions |
|---|---|
| A. Performs Common Occupational Skills | 20 |
| B. Performs Layout and Fabrication of Components for Welding | 28 |
| C. Performs Cutting and Gouging | 23 |
| D. Welding Processes | 54 |
By question type, this trade's exam runs 40 to 50% knowledge and recall, 35 to 45% procedural and application, and 10 to 20% critical thinking.
Already experienced? The Trade Equivalency Assessment
Workers with experience from outside Ontario's apprenticeship system, or from another country, can apply for a Trade Equivalency Assessment instead of starting an apprenticeship. Approval requires verifiable evidence of competency in the trade's Training Standard and experience at least equal to the trade's total training time; if approved, you challenge the certifying exam directly. The assessment costs $235 plus HST, and a reassessment with new evidence costs $100 plus HST, per Skilled Trades Ontario's Trade Equivalency Assessment page.
Certification is not the only paperwork
A Certificate of Qualification covers the person. Running a business in the trade carries its own obligations: many Ontario municipalities require a contractor licence on top of personal certification, and construction employers must complete WSIB registration before work begins. Both are indexed on our sister site: municipal contractor licensing requirements by city and WSIB Form 1000, registration of constructors and employers, on Ontario Trade Registry.
What does a welder earn in Ontario?
| Median wage | $28.00 per hour |
|---|---|
| Low | $21.00 |
| High | $41.28 |
| Occupation measured | Welders and related machine operators (NOC 72106) |
| Reference period | 2023-2024 |
Published by Employment and Social Development Canada through Job Bank, for Ontario as a whole. Read it as the pay range for the occupational group this trade belongs to, not a guaranteed rate: one NOC code can cover more than one trade, and wages vary by region, employer and experience.
Is the 456A recognised outside Ontario?
This trade has been part of the Interprovincial Red Seal Program since 1979. 13 of Canada's 13 provinces and territories designate it Red Seal: AB, BC, MB, NB, NL, NS, NT, NU, ON, PE, QC, SK, YT, Ontario among them. Its National Occupational Classification code is 72106, which is how federal labour market data refers to this occupation.
Where can you train as a welder in Ontario?
| Public training providers | 12 colleges deliver the in-school portion |
|---|---|
| Private training providers | 7 |
| Approved sponsors | 634 employers registered to train apprentices |
| Apprentices in training | 1,512 |
Counts are from Ontario's published apprenticeships dataset. A sponsor is the employer or union that registers and trains the apprentice; you need one before an apprenticeship can start.
How dangerous is industrial work in Ontario?
Ontario does not publish injury figures per trade, only by sector. In 2024 the Ministry of Labour recorded 27 worker fatalities and 2,148 critical injuries under the industrial health and safety program. See the ten-year counts and what they leave out.
Related Ontario trades
Other industrial sector trades with certification records on this registry:
Official verification sources
- RegulationO. Reg. 876/21, Prescribed Trades and Related Matters (e-Laws)
- Certifying bodySkilled Trades Ontario: Welder
- ActBuilding Opportunities in the Skilled Trades Act, 2021 (e-Laws)
- WagesJob Bank wage data, Employment and Social Development Canada
- Red Seal profilered-seal.ca: Welder trade profile
- Participation dataOntario open data: Apprenticeships dataset
Classification, exam requirement and ratio status on this page are read directly from O. Reg. 876/21 as consolidated on e-Laws, not from secondary summaries. Facts not yet verified against a primary source are marked as not published rather than estimated.