Deformed Steel Bar (rebar) Ø8 mm — Size, Weight, Grades & Specification

Shandong Dayang Deformed Steel Bar (rebar) in Ø8 mm: theoretical weight 0.395 kg/m taken from GB 1499.2-2024 Tables 2 and 4, 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 deformed bar of nominal diameter 8 mm weighs 0.395 kg per metre on the nominal area of 50.27 mm². It is produced to GB 1499.2-2024 as a hot-rolled ribbed bar in grade HRB400E, supplied straight in 6 m, 9 m or 12 m lengths or cut and bent to a bar schedule.

Nominal weight is a calculated figure, not a weighed one: it is derived from the nominal cross-section, so a bar inside the permitted dimensional deviation can differ from it. GB 1499.2-2024 sets that permitted deviation for this diameter at 5.5 %, which is the figure to use when you check a delivered bundle against the certificate.

On this page: the nominal weight, the permitted deviation, the inner-diameter check that distinguishes genuine ribbed bar from a re-rolled substitute, the full GB 1499.2-2024 size range with this diameter marked, chemistry and mechanical properties, and the applications this bar is ordered for.

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 1499.2-2024 Tables 2 and 4. Standard lengths: 6 m, 9 m and 12 m as standard; cut-and-bend to a bar schedule on request. Finish: Hot-rolled ribbed (deformed) surface; mill finish, no coating.

Nominal diameter	Area (mm²)	Theoretical weight (kg/m)	Weight per 12 m (kg)	Permitted deviation
Ø6 mm	28.27	0.222	2.7	5.5 %
Ø8 mm	50.27	0.395	4.7	5.5 %
Ø10 mm	78.54	0.617	7.4	5.5 %
Ø12 mm	113.1	0.888	10.7	5.5 %
Ø14 mm	153.9	1.209	14.5	4.5 %
Ø16 mm	201.1	1.58	19.0	4.5 %
Ø18 mm	254.5	1.999	24.0	4.5 %
Ø20 mm	314.2	2.468	29.6	4.5 %
Ø22 mm	380.1	2.986	35.8	4.5 %
Ø25 mm	490.9	3.856	46.3	3.5 %
Ø28 mm	615.8	4.837	58.0	3.5 %
Ø32 mm	804.2	6.318	75.8	3.5 %
Ø36 mm	1018	7.996	96.0	3.5 %
Ø40 mm	1257	9.872	118.5	3.5 %
Ø50 mm	1964	15.425	185.1	3.5 %

Theoretical weight is calculated from the nominal cross-section as W (kg/m) = 0.00617 × d² with d the nominal diameter in mm, and every value in the table above has been checked against the published GB 1499.2-2024 figures — the two agree to within 0.16 %. Nominal weight is a calculated figure; a bar inside the permitted dimensional deviation may weigh slightly more or less, and the permitted deviation is shown in the table.

Permitted deviation and inner diameter (this diameter marked in context)

Nominal diameter	Permitted deviation (batch weight)	Nominal inner diameter (mm)	Inner diameter tolerance	Nominal weight (kg/m)
Ø6 mm	5.5 %	5.8	±0.3	0.222
Ø8 mm	5.5 %	7.7	±0.4	0.395
Ø10 mm	5.5 %	9.6	±0.4	0.617
Ø12 mm	5.5 %	11.5	±0.4	0.888
Ø14 mm	4.5 %	13.4	±0.4	1.21
Ø16 mm	4.5 %	15.4	±0.4	1.58
Ø18 mm	4.5 %	17.3	±0.4	2
Ø20 mm	4.5 %	19.3	±0.5	2.47
Ø22 mm	4.5 %	21.3	±0.5	2.98
Ø25 mm	3.5 %	24.2	±0.5	3.85
Ø28 mm	3.5 %	27.2	±0.6	4.83
Ø32 mm	3.5 %	31	±0.6	6.31
Ø36 mm	3.5 %	35	±0.6	7.99
Ø40 mm	3.5 %	38.7	±0.7	9.87
Ø50 mm	3.5 %	48.5	±0.8	15.42

GB 1499.2-2024 controls ribbed bar two ways. The batch weight may deviate from the nominal weight by no more than the percentages above, and the inner diameter must stay inside the stated band. The inner-diameter check is the one that matters commercially: re-rolled bar made from scrap rail often passes on weight while failing on inner diameter, which shows up later as poor bond behaviour in concrete.

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
HRB400E	A615 Gr.60 (420)	B500B / EN 10080	SD390 (JIS G3112)	BSt420S	Hot-rolled ribbed bar (rebar), seismic (GB/T 1499.2)
HRB500E	A615 Gr.75 (520)	B500B (high grade) / EN 10080	SD490 (JIS G3112)	BSt500S	Hot-rolled ribbed bar (rebar), seismic (GB/T 1499.2)

Grade Notes

HRB400E — The most widely used reinforcement bar in China. The ‘E’ suffix indicates seismic (earthquake-resistant) performance.
HRB500E — High-strength seismic rebar, saves 10–15% steel tonnage versus HRB400 at equal load capacity.

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
HRB400E	≤0.25	≤0.80	≤1.60	≤0.045	≤0.045	Ceq ≤0.54
HRB500E	≤0.25	≤0.80	≤1.60	≤0.045	≤0.045	Ceq ≤0.55

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
HRB400E	≥400 MPa	—	≥540 MPa	—	—	—
HRB500E	≥500 MPa	—	≥630 MPa	—	—	—

Standards & Documents

GB 1499.2-2024 (steel for the reinforcement of concrete — hot-rolled ribbed bars)
EN 10080 / EN 1992-1-1 (Eurocode 2 design rules)
ASTM A615 / A706
BS 4449:2005

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
Reinforced concrete structures	Slabs, beams, columns and walls to Eurocode 2, ACI 318 or GB 50010 detailing rules.
Foundations and rafts	Mat and pile-cap reinforcement where ductility class E is normally specified.
Infrastructure and civil works	Bridges, retaining walls, tunnels and marine structures.
Seismic detailing	Grade HRB400E / HRB500E carry the enhanced ductility and Charpy requirements that seismic detailing rules rely on.
Industrial floors and hardstandings	Mesh and bar reinforcement in slabs on grade, often in cut-and-bent form.
Precast and prefabricated units	Cages fabricated to a bar schedule and delivered ready for casting.

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.

Re-rolled bar sold as genuine ribbed bar

Why it happens: Bar rolled from scrap rail can pass a weight check while failing the inner-diameter and rib-geometry requirements, which are what develop the bond with concrete.

Our control: We supply bar with the manufacturer’s mark rolled into the surface and an EN 10204 3.1 certificate traceable to the heat, and can supply a third-party inspection to GB 1499.2-2024 for critical structures.

Wrong ductility class for a seismic design

Why it happens: Plain HRB400 and HRB400E are not interchangeable: the E class carries the enhanced strength and elongation requirements that seismic detailing rules depend on.

Our control: We confirm the ductility class on the order and the certificate, and where the design is seismic we supply E-class bar only.

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 1499.2-2024 Tables 2 and 4), 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 deformed bar calculated?

The nominal weight is calculated from the nominal cross-section: W (kg/m) = 0.00617 × d², where d is the nominal diameter in millimetres. That is the figure the standard table is built on, and it is a calculated value — not a weighed one — which is why a bar inside the permitted dimensional deviation can weigh slightly more or less.

Then how do I check a delivered bundle?

Two ways. Compare the batch weight against the nominal weight, allowing the permitted deviation that GB 1499.2-2024 sets for that diameter — the table on this page gives it. Then measure the inner diameter, which must stay inside the stated band. The inner-diameter check catches re-rolled bar that passes on weight but fails on bond behaviour.

What is the difference between HRB400 and HRB400E?

The E denotes the enhanced ductility class. It carries tighter requirements on the ratio of measured to nominal strength and on elongation, which is what seismic detailing rules rely on. The two are not interchangeable in a seismic design, and the certificate has to state the class you specified.

What does Deformed Steel Bar (rebar) Ø8 mm weigh?

Deformed Steel Bar (rebar) Ø8 mm at Ø8 mm weighs 0.395 kg per metre, taken from GB 1499.2-2024 Tables 2 and 4. A 6 m length of this size weighs approximately 2.4 kg and a 12 m length approximately 4.7 kg.

How does HRB400E compare with B500B or Grade 60?

HRB400E is a 400 MPa nominal-yield ribbed bar with enhanced ductility; B500B to BS 4449 and Grade 60 to ASTM A615 are similar in concept but differ in the exact strength, ductility and rib-geometry requirements. Confirm equivalence against the design code your project is built to rather than by nominal grade, and state the standard on the order.

Do the bars carry a manufacturer’s mark?

Yes. Ribbed bar is rolled with the manufacturer’s identification mark and the bar size on the surface, and the certificate is issued against the heat number. Where a structure is subject to third-party inspection we can arrange an independent test to GB 1499.2-2024 before shipment.

What lengths and shapes do you supply?

Straight bar in 6 m, 9 m and 12 m, and cut-and-bent bar fabricated to a bar schedule with the bar marks shown on the bundle labels so the cage goes together on site without sorting.

How is the bar packed for sea freight?

Bundles are strapped with the size, grade, heat number and bar mark on the label. Straight bar is stowed on dunnage to keep it clear of the container floor, and loading photographs are retained as evidence of condition at departure.

Is rust on the surface a problem?

Surface rust on uncoated reinforcement is normal after sea transit and is not by itself a reason for rejection — the standards address section loss, not discolouration. Where a structure calls for it we can specify a light mill scale or an epoxy coating; tell us the exposure and we will match the finish to it.

What is the minimum order quantity?

It depends on diameter, lengths and whether the order can be consolidated into one container. Send the diameters, quantities, lengths or bar schedule and the destination port.

Who supplies deformed steel bar (rebar) from China with documentation?

Shandong Dayang supplies GB 1499.2-2024 ribbed bar with EN 10204 3.1 certification traceable to the heat, cut-and-bent fabrication to a bar schedule, and third-party inspection arranged on request.

Request a Quotation for Deformed Steel Bar (rebar) Ø8 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.