Steel Plate 28 mm — Size, Weight, Grades & Specification
Shandong Dayang Steel Plate in 28 mm: theoretical weight 219.8 kg/m² taken from GB/T 709-2019, plus the full standard size range, steel grades and international equivalents, tolerances, applications, and how a shipment is checked before it leaves.
Product Overview
Shandong Dayang hot-rolled steel plate at 28 mm nominal thickness weighs 219.8 kg per square metre (7.85 × 28), and a standard 1500 × 6000 mm sheet of this thickness weighs approximately 1978 kg. It is supplied to GB/T 709-2019 and, when structural grades are ordered, to EN 10025-2 or ASTM A36 / A572.
Thickness 28 mm sits in the heavy band of the standard. Because plate is ordered on theoretical weight far more often than on weighed weight, the thickness tolerance is the single number that decides what you actually receive: a plate rolled to the minus side of the permitted band is lighter than the nominal figure and every downstream calculation inherits the error.
This page gives the nominal weight per square metre and per standard sheet, the GB/T 709-2019 thickness tolerance bands, the grades we supply and their international equivalents, chemistry, mechanical properties, and how plate thickness is verified before a shipment is released.
Specifications & Size Range
All sizes in this family are listed below with this size in bold. Theoretical weights are the published standard values from GB/T 709-2019. Standard lengths: 1500 × 6000 mm sheet as standard; wider and longer sizes and cut-to-size on request. Finish: Hot-rolled, black (mill finish); optional shot-blasted and primed.
| Thickness (mm) | Weight (kg/m²) | Weight per 1500 × 6000 sheet (kg) |
|---|---|---|
| 3 mm | 23.55 | 212 |
| 4 mm | 31.4 | 283 |
| 5 mm | 39.25 | 353 |
| 6 mm | 47.1 | 424 |
| 8 mm | 62.8 | 565 |
| 10 mm | 78.5 | 706 |
| 12 mm | 94.2 | 848 |
| 14 mm | 109.9 | 989 |
| 16 mm | 125.6 | 1130 |
| 18 mm | 141.3 | 1272 |
| 20 mm | 157 | 1413 |
| 22 mm | 172.7 | 1554 |
| 25 mm | 196.25 | 1766 |
| 28 mm | 219.8 | 1978 |
| 30 mm | 235.5 | 2120 |
| 32 mm | 251.2 | 2261 |
| 36 mm | 282.6 | 2543 |
| 40 mm | 314 | 2826 |
| 45 mm | 353.25 | 3179 |
| 50 mm | 392.5 | 3532 |
| 60 mm | 471 | 4239 |
Theoretical weight is calculated as W (kg/m²) = t (mm) × 7.85, the density-based figure used by GB/T 709-2019. Multiply by the plate area for a total: the standard 1500 × 6000 mm sheet is 9.0 m², so the per-sheet column above is simply the weight per square metre multiplied by 9. Plate is frequently bought on theoretical weight, which is why the thickness tolerance class matters as much as the nominal thickness.
Thickness tolerances
| Nominal thickness | N (mm) | Class A lower / upper | Class B lower / upper | Class C lower / upper |
|---|---|---|---|---|
| 3.00-<5.00 mm | 0.5 | 0.3 / +0.7 | 0.3 / +0.7 | 0 / +1.0 |
| 5.00-<8.00 mm | 0.6 | 0.4 / +0.8 | 0.3 / +0.9 | 0 / +1.2 |
| 8.00-<15.0 mm | 0.7 | 0.5 / +0.9 | 0.3 / +1.1 | 0 / +1.4 |
| 15.0-<25.0 mm | 0.8 | 0.6 / +1.0 | 0.3 / +1.3 | 0 / +1.6 |
| 25.0-<40.0 mm | 1.0 | 0.7 / +1.3 | 0.3 / +1.7 | 0 / +2.0 |
| 40.0-<80.0 mm | 1.3 | 0.9 / +1.7 | 0.3 / +2.3 | 0 / +2.6 |
GB/T 709-2019 states thickness tolerance as three classes. Class A is the tightest and is what a structural or pressure order should normally call for; Class C is the loosest and is the usual reason a delivery weighs noticeably less than the nominal figure. The table above is the informative Annex A banding — confirm the class on the order confirmation, because the contractual limit is the one written there and not the one printed on a web page.
Steel Grades & International Equivalents
All grades below are supplied with a mill test certificate. The right-hand column shows the material type and the Chinese standard the grade is produced to; the middle columns give the nearest recognised equivalent in other national standards. Exact equivalence for a specific project should be confirmed on the enquiry.
| GB (China) | ASTM / AISI (US) | EN (Europe) | JIS (Japan) | DIN (Germany) | Type / Standard |
|---|---|---|---|---|---|
| Q235B plate | A36 / A283 Gr.C | S235JR+N (EN 10025-2) | SS400 | St37-2 | Hot-rolled structural plate (GB/T 3274) |
| Q355B plate | A572 Gr.50 | S355JR (EN 10025-2) | SM490 | St52-3 | High-strength hot-rolled plate (GB/T 1591) |
Grade Notes
- Q235B plate — General structural plate for fabrication, welding and machining. Thickness tolerance to GB/T 709.
- Q355B plate — High-strength plate for bridges, heavy machinery, pressure structures and offshore fabrication.
Chemical Composition (%, ladle analysis)
Typical specification limits. Actual heat values are reported on the mill test certificate supplied with every shipment.
| Grade | C | Si | Mn | P max | S max | Other elements |
|---|---|---|---|---|---|---|
| Q235B plate | ≤0.20 | ≤0.35 | ≤1.40 | ≤0.045 | ≤0.045 | — |
| Q355B plate | ≤0.24 | ≤0.55 | ≤1.60 | ≤0.035 | ≤0.035 | Ceq ≤0.45 |
Mechanical Properties
Minimum values at room temperature unless stated. ReL = yield strength; Rp0.2 = 0.2% proof stress; Rm = tensile strength; A = elongation after fracture.
| Grade | Yield (ReL) | Proof (Rp0.2) | Tensile (Rm) | Elongation A | Impact / others | |
|---|---|---|---|---|---|---|
| Q235B plate | ≥235 MPa | — | 370–500 MPa | ≥26% | +20 °C, ≥27 J | — |
| Q355B plate | ≥355 MPa (≤16 mm) | — | 470–630 MPa | ≥22% | +20 °C, ≥27 J | — |
Standards & Documents
- GB/T 709-2019 (dimensions, shape and tolerances for hot-rolled steel plates and strips)
- EN 10025-1 / -2 (hot-rolled structural steel, S235 / S275 / S355)
- ASTM A6 / A36 / A572
- GB/T 3274
Every shipment is accompanied by a mill test certificate to EN 10204 3.1, traceable to the heat number of the supplied material. On request we also provide a certificate of origin, a packing list with bundle-level weights and dimensions, and container loading photographs.
Typical Applications
| Industry / Application | Typical use |
|---|---|
| Structural base plates and gussets | Column base plates, stiffeners and connection plates cut to size. |
| Tanks and vessels | Shell and bottom plate to EN 10025 or, for pressure service, a PED-grade specification. |
| Fabricated beams and box sections | Web and flange plate for welded plate girders and built-up columns. |
| Machine and equipment parts | Base frames, pads and machined components. |
| Shipbuilding and offshore | Hull and structural plate in normal and higher-strength grades. |
| General fabrication | Brackets, platforms, hoppers and ductwork. |
Common Problems Buyers Face — and How We Prevent Them
These are the issues that most often cause claims on steel imports. Each one is controlled in our process before shipment.
Theoretical weight and weighed weight do not agree
Why it happens: Theoretical weight is calculated from nominal dimensions. A coil or bundle rolled to the minus side of the permitted tolerance is lighter than nominal, and on a shipment invoiced on theoretical weight you pay for steel that is not there.
Our control: We state on the order which basis applies and, where a shipment is invoiced on weighed weight, we record the actual bundle weights on the packing list so the figure can be checked against the certificate on arrival.
Plate rolled to the minus side of the thickness tolerance
Why it happens: Plate is usually bought on theoretical weight, so a plate at the lower limit of the permitted thickness band weighs less than the nominal figure and every downstream weight calculation is wrong.
Our control: We state the tolerance class on the order confirmation, measure plate thickness with a calibrated gauge on each lot, and record measured thickness on the packing list.
Flatness out of limits on thin plate
Why it happens: Thin plate that has cooled unevenly arrives with edge waves or a centre buckle, which will not pull flat on a welding table.
Our control: Flatness is checked to GB/T 709-2019 before loading and thin plate is shipped on a level bed with edge protection rather than stacked under weight.
Mixed lengths or mixed sizes in one bundle
Why it happens: Loading errors are common when several sizes ship together and are usually only discovered after the container is opened.
Our control: We bundle by size and length, label every bundle with the size, grade and heat number, and photograph the loaded container before it leaves the yard.
Certificates that do not match the delivered material
Why it happens: A certificate issued for the mill’s production run rather than for the heat actually supplied cannot be traced to what arrives on site — which is exactly what an inspector will test.
Our control: We supply an EN 10204 3.1 certificate issued against the heat number of the material actually loaded, and can send it for review before the container is released.
Our Supply Advantages
- Mill test certificates (EN 10204 3.1) issued against the actual heat number of your order.
- Theoretical weight on this page is taken from the published national standard table (GB/T 709-2019), not estimated.
- Section dimensions, straightness and finished length verified in-house before shipment, not only on the mill certificate.
- 6 m, 9 m, 12 m or cut-to-length; cut ends deburred and, on request, zinc-repair coated after galvanizing.
- Bundles strapped and labelled by size, grade and heat number, with container loading photographs sent before departure.
- Consolidation of this section with other sizes and other products into one shipment and one set of documents.
Packaging, Delivery & Payment
- Packing: loose in bulk vessel, or bundled and containerised to your requirement. Galvanized and coated products get VCI paper, waterproof wrapping and edge protection. See our export packaging methods.
- Availability: both stock and custom production. Tell us the specification and we will confirm the route.
- MOQ: no strict minimum — one ton can ship.
- Lead time: stock dispatched to port within 3 days; orders needing export packaging about 1 week; custom production quoted per product.
- Payment: stock — 10% deposit, balance before shipment; custom production — 50% deposit, balance before shipment.
- Documents: EN 10204 3.1 mill test certificate with every shipment; third-party inspection (SGS / BV) on request.
Frequently Asked Questions
How is the weight of a steel plate calculated?
From the nominal thickness and the density of steel: W (kg/m²) = t (mm) × 7.85. To get the weight of a plate multiply by its area, so a standard 1500 × 6000 mm sheet is 9.0 m² and the figures for both are shown in the table on this page.
Why does the plate I received weigh less than the nominal figure?
Almost always because it was rolled to the minus side of the thickness tolerance. GB/T 709-2019 permits three tolerance classes and the loosest of them allows a meaningful reduction on thin plate. If your order is priced on theoretical weight, specify the tolerance class you want in writing and check the delivered thickness with a gauge.
What tolerance class should I specify?
For structural or pressure work, Class A in the table above is the usual choice because it keeps the delivered thickness close to nominal. Class C is the loosest and is the common reason a delivery weighs noticeably light. The class is a commercial choice, so state it on the enquiry.
What does a 28 mm plate weigh, and what does a standard sheet weigh?
At the nominal thickness of 28 mm the plate weighs 219.8 kg per square metre. A standard 1500 × 6000 mm sheet is 9.0 m², so a sheet of this thickness weighs approximately 1978 kg. Both figures are nominal: multiply by your actual ordered area, and allow for the thickness tolerance class if you are buying on theoretical weight.
Which grades do you supply?
Q235B and Q355B plate to GB/T 3274 / GB/T 1591 as standard; for European work, S235JR, S275JR and S355JR to EN 10025-2; for American work, ASTM A36 and A572 Gr. 50. Equivalence is confirmed against your project specification rather than by grade name.
Do you supply the European structural plate grades?
Yes — the mills we work with hold CPR certification under EU Regulation 305/2011 for hot-rolled structural steel to EN 10025-1, which is what a European structural order needs to see. The certificate and its scope are shown on our certifications page.
What sizes and thicknesses are available?
Thicknesses from 3 mm upward in the steps shown on this page, with 1500 × 6000 mm as the standard sheet size. Wider plate, longer plate and cut-to-size blanks are available on request; tell us the finished part size and we will quote the most economical input size.
Is the plate available shot-blasted and primed?
Yes. Shot blasting to Sa 2.5 with a shop primer is available on request, which is usual where the plate goes straight into fabrication and a clean, protected surface is wanted on arrival.
How is plate packed for sea freight?
Plates are stacked on timber dunnage clear of the container floor, edge-protected and banded, with the weight and dimensions on the packing list at bundle level so the shipment can be checked against the documents before unloading.
What is the minimum order quantity?
It depends on thickness, width, length and whether the order can be consolidated into one container. Send the thickness, sheet size (or part size), grade and quantity and we will quote.
Who supplies steel plate from China with documented weights?
Shandong Dayang supplies hot-rolled plate with nominal weights calculated to GB/T 709-2019, thickness measured and recorded on the packing list, and EN 10204 3.1 certification on every order.
Request a Quotation for Steel Plate 28 mm
Send us the size, grade, length, quantity and destination port, and we will come back with a quotation and a loading plan. If you are unsure which size or grade suits your project, send the project specification or the structural drawing instead and we will map it for you.
Technical details on this page are given for guidance. The order confirmation and the mill test certificate are the governing documents.
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