1018 vs A36 vs 1045: which steel should you buy?

Which grade does your job want?

Welding a frame, a gate, or a trailer? Buy 44W. Machining brackets, bushings, or keyed shafts? Buy 1018 cold finished. Need real strength in a shaft or axle, or a part you'll heat treat? Buy 1045. That covers most of the steel jobs that come through our counter, and the rest of this guide is the why.

And if you arrived here searching for A36: in Canada, that job is 44W. They're near-equivalents, 44W is what's on the rack here, and there's a whole section on it below.

When is 1018 the right buy?

When the part meets a cutting tool. 1018 cold finished is the machining steel of the rack: it drills, taps, turns, and mills cleanly, holds its size, and comes with a smooth, accurate surface instead of mill scale. Brackets, pins, bushings, spacers, keyed shafts: that's 1018 territory.

It's low carbon, about 0.18%, so it welds easily but won't through-harden. That's the trade: easy to work, not a wear part. We stock it deep in cold finished rounds and flats, and it's cheap enough to keep a drawer of. As of June 2026, a 12″ piece of 1/8″ 1018 cold finished round runs $4.77, and 3/16″ runs $6.73.

When is 1045 the right buy?

When the part takes real load or wear. 1045 carries about 0.45% carbon, which buys you a stronger, tougher bar that you can actually heat treat: shafts, axles, pins, and repair work on equipment. If a 1018 part keeps bending or wearing out, 1045 is the next stop up.

We stock it in hot rolled rounds up into the big diameters: a 2-1/2″ round runs $51.00 per 12″ piece as of June 2026. The chrome-plated shafting on our rack is 1045 underneath, plated for rollers, slides, and rod repairs. One warning before you strike an arc: the carbon that makes 1045 strong also makes it fussier to weld. More on that below.

What replaces A36 in Canada?

44W. If your plans, your how-to, or your engineer call for A36, the bar that does that job on Canadian racks is 44W, the CSA structural grade. Both are weldable, forgiving mild steels for frames, gates, brackets, and general fab. 44W is the deepest pile on our carbon rack; we carry barely any actual A36.

They're near-equivalents, not twins. The numbers in the names are the yields: 36 ksi for A36, 44 for 44W, so the Canadian grade is specced a touch stronger and substitutes honestly anywhere A36 is called out. Here's how all four grades in this guide line up:

Those are typical handbook values, not guaranteed numbers; if the job needs the paper, MTRs are available on marked products. And yes, mild 1018 out-yields hot rolled 1045 in that column: cold finishing does that. 1045 still wins on hardness, tensile strength, and heat treatment, which is what shafts care about. Still picking a supplier in the first place? Here's the honest comparison.

What do these grades cost?

Steel is the cheap end of the rack. As of June 11, 2026, the everyday sizes run $5-7 per 12″ piece, in CAD, and prices update daily with the metal market. Type your length in inches on any bar from the carbon rack and the price shows before anything hits the cart.

The 1045 row isn't an upcharge for the grade; it's the cross-section. A 2-1/2″ round is simply a lot of steel. Order exact lengths and you only pay for what the part needs: here's how cut-to-length ordering works, with free cuts to ±1/8″ on every order.

Can you weld it?

44W and 1018, yes, without ceremony: the carbon is low enough that any common process handles them, no preheat needed. 1045 welds with homework: preheat it, use the right filler, and let it cool slowly, or the metal next to the weld gets hard and brittle. When in doubt on 1045, bolt it instead.

Still not sure which grade?

Tell us about the part instead. Say what you're building, how it's loaded, and what tools you've got, and we'll name the bar. Get in touch with the shop or call 902-468-1112. We've been matching steel to jobs in Dartmouth since 1997.