Steel fabrication is the process of turning raw steel from the mill (beams, plate, tube, angle, channel and bar) into finished components made to a drawing. A fabricator cuts, drills, bends, fits and welds the steel, then cleans, coats, marks and ships each piece so it can be installed on site without further work. On a building, that means beams with their connection plates already attached, columns with base plates, lintels, stairs, frames, and bent reinforcing bar, all made to fit one specific project.
This overview explains what fabrication covers, the main kinds of fabrication work, how it differs from the trades around it, and the Canadian standards behind it. For the shop floor step by step, see the structural steel fabrication process.
What steel fabrication means
The simplest way to understand fabrication is to look at what goes in and what comes out.
What goes in:
- Mill products: wide-flange beams, HSS tube, angle, channel, plate and flat bar, and reinforcing bar.
- The project's drawings: the engineer's structural drawings, then shop drawings prepared from them.
- Bolts, welding consumables and coatings.
What comes out:
- Finished, numbered pieces that match the drawings to fabrication tolerances.
- Each piece marked for its location, with paperwork showing what was shipped.
The value a fabricator adds is in the work between the two: knowing exactly what each piece needs, making it accurately, and making it so it goes together on site. A beam that arrives cut to length, drilled, with its plates welded on and a mark that matches the erection plan is fabricated steel. The same beam sold as a raw length is stock.
Mills make the shapes; fabricators make the parts. The supply chain is covered in more detail in who makes steel beams in Canada.
The main types of steel fabrication work
"Steel fabrication" covers several related trades. Most shops specialize in one or two.
| Type | What it produces | Typical customers |
|---|---|---|
| Structural steel fabrication | Beams, columns, bracing, posts, lintels and their connections | General contractors, builders, homeowners through their contractor |
| Miscellaneous steel fabrication | Stairs, railings, ladders, gates, frames, supports and brackets | Builders, architects, renovators |
| Rebar fabrication | Reinforcing bar cut and bent to shape, tagged and bundled | Concrete and forming contractors |
| Plate and heavy fabrication | Tanks, hoppers, built-up girders, equipment bases | Industrial and mining clients |
| Sheet metal and light gauge work | Ductwork, flashings, enclosures, cold-formed framing | Mechanical and envelope trades |
The first three are the construction side of the trade and are what Procut does. Each has its own guide: miscellaneous metal fabrication and what is rebar fabrication? cover the second and third in detail.
How steel fabrication works
Every fabrication job follows roughly the same flow, whether it is one basement beam or a warehouse frame:
- Drawings. The structural design is turned into shop drawings that define every piece. See what is steel detailing?
- Material. Steel is ordered or pulled from stock in the grades the design calls for, with mill certificates where the project requires them.
- Cutting. Members are cut to length by saw, and plates and shapes cut by plasma, oxy-fuel or similar methods.
- Holes and copes. Bolt holes are drilled or punched, and beam ends are coped to clear other members.
- Bending and rolling, where the piece needs a curve or bend, or bar needs bending to a shape.
- Fitting. Plates, stiffeners and clips are located and tacked in place against the drawing.
- Welding. Fitted parts are welded to approved procedures by qualified welders.
- Inspection. Dimensions and welds are checked before the piece leaves the shop.
- Cleaning and coating. Steel is cleaned and left bare, primed, painted or galvanized as specified.
- Marking and shipping. Each piece is marked, loaded in erection order where possible, and delivered.
The individual processes (cutting, drilling, bending, welding, coating) are compared in types of steel fabrication processes.
Fabrication vs welding, supply and erection
Steel fabrication is often confused with the trades on either side of it. The differences matter when you are deciding who to call and comparing quotes.
- Fabrication vs welding. Welding is one operation inside fabrication. A welder joins metal; a fabricator takes responsibility for the whole piece, from the drawing to the delivered part. Plenty of fabricated steel has little welding at all. See steel fabrication vs welding.
- Fabrication vs supply. A steel service centre sells stock lengths and may cut to length. It does not make project-specific components with connections. Some companies, Procut included, do both: supply steel cut to length or fully fabricated to your drawings.
- Fabrication vs erection. Fabrication happens in the shop; erection is lifting the pieces into place and connecting them on site. One company can do both or they can be separate contracts. See steel fabrication vs erection.
- Fabrication vs design. The fabricator builds what the engineer of record designed. Where connection design is delegated to the fabricator, an engineer working for the fabricator designs those connections. A fabricator does not resize your beams.
Standards and certification in Canada
Structural steel fabrication in Ontario is not a free-for-all. The 2024 Ontario Building Code requires buildings and structural members made of structural steel to conform to CSA S16, Design of steel structures (Article 4.3.4.1.), and its explanatory note points to the clause of S16 that sets out qualification for fabricators and erectors of welded construction. In practice that chain means:
- CSA S16 sets the design rules plus requirements for fabrication, erection and tolerances.
- CSA W59 governs welded steel construction: weld design, workmanship and inspection.
- CSA W47.1 covers certification of companies that weld steel, administered by the Canadian Welding Bureau (CWB).
- CSA G40.21 and ASTM standards define steel grades, such as 350W for many Canadian shapes.
Rebar fabrication works to its own set of standards for bar, bending and detailing. Our summary of steel fabrication standards in Canada goes through who each standard applies to, and why hire a CWB certified fabricator explains what certification checks.
What a fabricator needs from you
The accuracy of fabricated steel depends on the information that goes in. To get a firm quote and fabricated pieces that fit, send:
- The structural drawings, current and complete, with the specification if there is one.
- Architectural drawings, where steel meets openings, finishes, stairs or cladding.
- Who designs the connections, if it is not shown on the drawings.
- The coating: bare, primed or galvanized, and whether it will be exposed or concealed. See does structural steel need paint or galvanizing?
- Site details: access, delivery constraints and whether you need installation or delivery only.
- Your schedule, including phasing if the job goes up in stages.
For a house, the starting point is usually the permit drawings from your designer or engineer. Structural changes such as removing a bearing wall need a qualified designer or engineer, and usually a building permit, before any steel is ordered.
Steel fabrication at Procut
Procut Steel fabricates structural steel, miscellaneous steel and rebar from our shop in Erin, Ontario. We prepare shop drawings in-house, cut, fit, weld (CWB certified), grind, mark and bundle every piece to match the drawings, prime or galvanize to suit, and deliver across the GTA and Ontario. For structural steel and rebar, we can also install, from basement beams and posts to larger commercial projects.
Send us your structural or architectural drawings and we will prepare a free take-off and quote. Request a quote, or see what we make on our services page.
Frequently asked questions
What is steel fabrication in simple terms?
Steel fabrication is making finished steel parts from raw steel. A fabricator takes beams, plate, tube, angle, channel or bar from the mill and cuts, drills, bends, fits and welds it into components built to a drawing, ready to install.
What does steel fabrication work involve?
Reading drawings, ordering material, cutting to length, making holes and copes, bending or rolling where needed, fitting parts together, welding, inspecting, cleaning and coating, then marking and shipping each piece to site.
Is steel fabrication the same as welding?
No. Welding is one process within fabrication. Fabrication also includes detailing, cutting, drilling, bending, fitting, inspection, coating and logistics. Many fabricated pieces are bolted on site with very little welding at all.
What is the difference between a steel fabricator and a steel supplier?
A supplier or service centre sells steel as stock, sometimes cut to length. A fabricator turns that steel into finished components to a specific project's drawings, with holes, plates, connections and coatings, and marks each piece for its location.
