B500B Steel Rebar — Reinforcing Bar to DIN 488 / EN 10080
B500B steel rebar is the high-ductility, hot-rolled ribbed reinforcing bar at the heart of German and EU concrete construction. We supply B500B in 8–40 mm diameters as straight bar or cut-and-bend, with a full Mill Test Certificate to EN 10204 3.1 for export worldwide.
What is B500B steel rebar?
B500B steel rebar is a hot-rolled, ribbed reinforcing bar with a minimum characteristic yield strength of 500 MPa and ductility class B. It is the standard structural reinforcing bar specified across Germany and the European Union under DIN 488 and EN 10080, and is the bar most concrete designs to Eurocode 2 (EN 1992-1-1) assume by default. The “B500” designation means 500 MPa minimum yield; the trailing letter “B” denotes the ductility class — high ductility — which sits between the normal-ductility class A and the seismic-grade class C.
Because it is hot-rolled rather than cold-worked, B500B combines reliable strength with the elongation and strain-hardening reserve that engineers rely on for safe load redistribution and crack control. In practice it is the everyday workhorse of reinforced concrete: foundations, columns, beams, slabs, retaining structures and infrastructure all depend on it. The German legacy designation BSt 500 S corresponds to the same material class. Surface ribs give the mechanical bond to concrete that lets reinforced concrete behave as a composite material.
Why specify B500B
- 500 MPa yield — efficient design, less steel per cubic metre of concrete than older 220/420-grade bars.
- High ductility (class B) — ratio of tensile to yield strength (k = Rm/Re) ≥ 1.08 and total elongation at maximum force Agt ≥ 5.0 %, giving warning before failure.
- Hot-rolled, weldable — controlled chemistry (low carbon equivalent) suits site and shop welding to DIN EN ISO 17660.
- Standardised worldwide — DIN 488 / EN 10080 properties are recognised across European, Middle East, African and many international markets.
B500B mechanical properties
The characteristic mechanical requirements for B500B reinforcing steel are defined by DIN 488-1 and EN 10080 / EN 1992-1-1 Annex C. These are the values the design engineer uses and the values the Mill Test Certificate confirms for each heat.
| Property | Symbol | B500B requirement |
|---|---|---|
| Characteristic yield strength | Re (fyk) | ≥ 500 MPa |
| Tensile / yield ratio | k = Rm/Re | ≥ 1.08 |
| Total elongation at max. force | Agt | ≥ 5.0 % |
| Ductility class | — | Class B (high) |
| Modulus of elasticity | Es | ≈ 200 GPa |
B500B vs B500A vs B500C
All three grades share the same 500 MPa minimum yield — they differ only in ductility. B500A (normal ductility) requires k ≥ 1.05 and Agt ≥ 2.5 %, and is frequently cold-rolled for coil and welded mesh. B500B is the high-ductility hot-rolled workhorse bar (k ≥ 1.08, Agt ≥ 5.0 %). B500C is the seismic / high-demand grade with 1.15 ≤ k < 1.35 and Agt ≥ 7.5 %, specified where capacity design or high seismic ductility is required. For most general structural reinforcement outside seismic zones, B500B is the correct and economical choice. See our steel grades overview for a full comparison.
Chemical composition & weldability
B500B is supplied with a controlled, low-alloy chemistry that guarantees both consistent strength and good weldability. EN 10080 / DIN 488 cap the principal elements on the cast (ladle) analysis:
| Element | Maximum (cast analysis) | Role |
|---|---|---|
| Carbon (C) | ≤ 0.24 % | Strength; limited to protect weldability |
| Phosphorus (P) | ≤ 0.055 % | Limited to avoid embrittlement |
| Sulphur (S) | ≤ 0.055 % | Limited for ductility & weldability |
| Nitrogen (N) | ≤ 0.013 % | Controls strain-ageing |
| Copper (Cu) | ≤ 0.85 % | Residual control |
| Carbon equivalent (Ceq) | ≤ 0.50 % | Governs weldability |
The capped carbon equivalent (Ceq) is what makes B500B reliably weldable. Welding of reinforcing steel — lap, butt, cross and other joints — is carried out to DIN EN ISO 17660, which sets out approved processes, welder qualification and joint testing for load-bearing and non-load-bearing welds. This makes B500B suitable for prefabricated cages, mechanical fixing and on-site connections where welding is specified.
Rib geometry & bond
What distinguishes reinforcing bar from plain round steel is its surface ribbing. B500B bars carry two or more rows of transverse ribs at a controlled height, spacing and inclination, defined by the relative rib area (fR) requirement in DIN 488 / EN 10080. This geometry creates the mechanical bond between steel and concrete that allows reinforced concrete to act as a composite — transferring tensile force from the concrete into the steel and back across cracks. Adequate bond is also what controls crack widths and lets designers develop and lap bars over reasonable lengths per Eurocode 2.
The rib pattern additionally serves as an identification mark: rolling marks on the bar encode the producing mill and country, allowing each bar to be traced back to its certificate. Combined with the high ductility of class B and the weldability described above, the ribbed profile makes B500B a fully engineered, traceable reinforcement product rather than a commodity.
B500B dimensions & weights
We supply B500B steel rebar across the full DIN 488 diameter range, 8–40 mm. Theoretical mass is calculated as kg/m = d²(mm) × 0.00617 and cross-sectional area as A = π/4 · d². Use the table below for take-off and shipping weight estimates.
| Nominal diameter (mm) | Mass (kg/m) | Cross-section (mm²) |
|---|---|---|
| 8 | 0.395 | 50.3 |
| 10 | 0.617 | 78.5 |
| 12 | 0.888 | 113 |
| 14 | 1.21 | 154 |
| 16 | 1.58 | 201 |
| 20 | 2.47 | 314 |
| 25 | 3.85 | 491 |
| 28 | 4.83 | 616 |
| 32 | 6.31 | 804 |
| 40 | 9.86 | 1257 |
Standard straight bar is supplied in stock lengths of 6–18 m, with 12 m the most common export length. Other cut lengths are available to order, and bars can be processed to BS 8666 / DIN 488 shape codes. Bundles are tied and tagged for identification; seaworthy bundles are typically around 2 t for container or break-bulk shipment.
Forms supplied
B500B is available in the form that best suits your fabrication workflow.
Straight bar
Cut-to-length straight B500B in 8–40 mm, stock lengths 6–18 m (12 m common). Bundled, tagged and ready for site or shop fabrication.
Cut & bend
Bars processed to BS 8666 / DIN 488 shape codes — links, stirrups, bent bars and cages — delivered job-ready. Cut & bend service →
Coil
B500A/B500B in coil, 6–16 mm, for automated stirrup and mesh machines and continuous high-volume production. Rebar coils →
Applications of B500B rebar
The default structural reinforcing bar for the full spectrum of reinforced-concrete work.
Foundations & piling
Pile cages, pad and raft foundations, ground beams. More →
Infrastructure & bridges
Decks, abutments, retaining walls and culverts. More →
Columns & high-rise
Columns, cores, shear walls and floor slabs in framed buildings.
Slabs & general RC
Suspended slabs, beams and walls across commercial and industrial builds.
Ordering & export documentation
Every consignment of B500B steel rebar is supplied with the documentation international buyers and inspection bodies require. Standard export paperwork includes a Mill Test Certificate to EN 10204 3.1 confirming the chemical and mechanical properties of each heat, a Certificate of Origin, a CE Declaration of Performance where applicable, and a detailed packing list. Bundles are marked and tagged so each can be matched to its certificate on arrival.
Tell us your diameters, lengths, total tonnage, required forms (straight, cut-and-bend or coil) and destination port, and we will respond with a detailed quotation. We arrange seaworthy bundling and container or break-bulk shipment to ports worldwide. See export & delivery and standards & certification for full details, or browse the complete product range.
B500B steel rebar — FAQ
Common questions from contractors, importers and project buyers.
What does B500B mean?
What is the difference between B500A, B500B and B500C?
Is B500B weldable?
What sizes and lengths are available?
What certificates are supplied with B500B?
Can you export B500B worldwide?
Source German-standard rebar with full export documentation
Tell us your specification and destination port — we’ll respond with a detailed quotation.