Steel plate in Canada is sold by thickness, width and length, almost always in imperial sizes. The familiar 4 x 8 ft sheet (1219 x 2438 mm) is the most common size people ask for, along with 4 x 10 and 5 x 10 ft. Mill plate comes much larger, with widths such as 60, 96 and 120 in and lengths of 240 and 480 in (20 and 40 ft). A 2400 x 1200 mm sheet is a metric size used in Europe and elsewhere; in Canada it's usually supplied from a 4 x 8 sheet, which is 19 mm wider and 38 mm longer. Below are the common sizes, what each weighs at popular thicknesses and how to order.
Common steel plate and sheet sizes
| Size (ft) | Size (in) | Metric (mm) | Area (m²) | Where you'll see it |
|---|---|---|---|---|
| 4 x 8 | 48 x 96 | 1219 x 2438 | 2.97 | Service centre and retail cut sheets |
| 4 x 10 | 48 x 120 | 1219 x 3048 | 3.72 | Service centre cut sheets |
| 5 x 10 | 60 x 120 | 1524 x 3048 | 4.65 | Service centre cut sheets |
| 5 x 20 | 60 x 240 | 1524 x 6096 | 9.29 | Mill plate |
| 8 x 20 | 96 x 240 | 2438 x 6096 | 14.86 | Mill plate |
| 10 x 20 | 120 x 240 | 3048 x 6096 | 18.58 | Mill plate |
| 8 x 40 or 10 x 40 | 96 or 120 x 480 | 2438 or 3048 x 12192 | 29.7 or 37.2 | Mill plate, heavy users |
The mill plate widths and lengths reflect one major North American plate distributor's published stock list, which also notes that the thickest plates come in narrower widths and shorter lengths. Exact sizes vary by supplier and by thickness, so ask what's on hand. Checker (floor) plate follows similar sheet sizes; see steel checker plate.
Sheet vs plate. In the trade, flat steel under about 1/4 in (6.4 mm) is usually sold as sheet and ordered by gauge, and 1/4 in and thicker is plate. That's why "4 x 8 steel plate" listings often start at 3/16 or 1/4 in. For thicknesses, see our steel plate thickness chart.
4 x 8 vs 2400 x 1200
If your drawings or a supplier abroad call for 2400 x 1200 mm, here's how it compares:
| 2400 x 1200 mm | 4 x 8 ft | |
|---|---|---|
| Width | 1200 mm | 1219 mm |
| Length | 2400 mm | 2438 mm |
| Area | 2.88 m² | 2.97 m² |
The 4 x 8 sheet is about 3% larger in area. If the full sheet is going into a frame, opening or layout designed for 1200 x 2400, ask for it trimmed to size; otherwise you'll be cutting 19 mm and 38 mm strips off on site. The same applies to 1500 x 3000 mm (metric) against 5 x 10 ft (1524 x 3048 mm).
Metric thicknesses work the same way. A drawing calling for 10 mm or 12 mm plate is often supplied as 3/8 in (9.5 mm) or 1/2 in (12.7 mm). That's a design change for structural parts, so the designer should accept it.
Sheet weights at common thicknesses
Weights are calculated from a steel density of 7,850 kg/m³ and rounded. Real plate can be slightly heavier or lighter within mill tolerances.
| Sheet | 3/16 in (4.8 mm) | 1/4 in (6.4 mm) | 3/8 in (9.5 mm) | 1/2 in (12.7 mm) | 3/4 in (19.1 mm) | 1 in (25.4 mm) |
|---|---|---|---|---|---|---|
| 4 x 8 ft | 111 kg | 148 kg | 222 kg | 296 kg | 445 kg | 593 kg |
| 4 x 10 ft | 139 kg | 185 kg | 278 kg | 370 kg | 556 kg | 741 kg |
| 5 x 10 ft | 174 kg | 232 kg | 347 kg | 463 kg | 695 kg | 926 kg |
| 8 x 20 ft | 556 kg | 741 kg | 1,111 kg | 1,482 kg | 2,223 kg | 2,964 kg |
Two things stand out. First, a single 4 x 8 sheet of 1/4 in plate is about 148 kg, which is too heavy to move casually by hand; plan to handle it with a forklift, plate clamp or hoist. Second, thick plate gets heavy very quickly, so it's usually cut to parts before it goes anywhere near a job site. To work out the weight of any piece, use our steel plate weight calculator.
Full sheets or cut to size?
Most structural plate never leaves the shop as a full sheet. Base plates, cap plates, connection plates, stiffeners and gussets are cut from larger plate to the dimensions on the drawings.
Buy a full sheet when you need the whole sheet (covers, liners, a floor or a large panel), or you're cutting many parts yourself and have the equipment.
Order cut to size when you need specific parts with holes, slots or bevels. You pay for the plate used plus a share of the offcut (the drop), and the cutting. It saves handling heavy sheets and site cutting, and the parts arrive ready to install.
How the parts nest into a stock plate affects how much steel you buy. Ordering parts in the same thickness and grade together helps, and so does giving the fabricator flexibility on which way parts are cut. Our guide to steel plate cut to size in Ontario compares the cutting methods and what to put on the order.
Grades and what the size doesn't tell you
The size and thickness don't say anything about strength. Structural plate in Canada is commonly CSA G40.21 300W or 350W, or ASTM A36 or A572 Grade 50, and abrasion-resistant and other special plates exist for wear and specialty uses. A drawing that says "PL 12" or "PL 1/2" should also say which grade. If it doesn't, ask the designer. See steel plate grades in Canada for the differences.
What to send when ordering plate
- Thickness and grade, in the units on your drawing.
- Full sheets: the sheet size and quantity.
- Cut parts: a drawing or DXF for each part with overall dimensions, hole sizes and locations, slots, bevels and corner details, plus quantities.
- Welding: whether the plate is welded to a post, beam or other part.
- Finish: mill finish, primer or galvanizing.
- Delivery: site address and any access limits.
We cut and drill base plates, cap plates and connection plates to your details, and weld them to posts and beams where the drawings call for it, with CWB certified shop welding.
Send your plate list or drawings for a quote, or browse our steel products, including plates, posts and beams.
Frequently asked questions
What size does steel plate come in?
In Canada, steel plate is generally sold in imperial sizes. Service centres commonly sell cut sheets such as 4 x 8 ft, 4 x 10 ft and 5 x 10 ft, while mill plate comes much larger, in widths such as 60, 96 and 120 in and lengths such as 240 and 480 in.
Is 2400 x 1200 the same as a 4 x 8 sheet?
Close, but not the same. A 4 x 8 ft sheet is 1219 x 2438 mm, slightly larger than 1200 x 2400 mm. In Canada a 2400 x 1200 request is usually filled from a 4 x 8 sheet, either full size or trimmed to the metric dimensions.
How much does a 4x8 sheet of 1/4 inch steel plate weigh?
About 148 kg (roughly 327 lb). A 4 x 8 ft sheet is 2.97 square metres, and 1/4 in (6.4 mm) plate weighs about 49.8 kg per square metre.
Can I buy steel plate cut to size?
Yes. Most structural plate parts, such as base plates, cap plates and connection plates, are ordered cut to size from a drawing rather than as full sheets. You pay for the plate used plus a share of the offcut, and the cutting itself.
