Steel & Rebar Resources, Specs & Glossary
The working reference desk for engineers, contractors and procurement teams. Rebar weight charts, grade comparisons across BS 4449, ASTM A615 and ISO 6935, standards explained in plain English, and a 30+ term reinforcement-steel glossary — built around the questions our export clients ask before they buy.
Rebar Unit Weight — Ø8 to Ø40 mm (kg/m)
Nominal masses for hot-rolled ribbed reinforcing bar, calculated by the standard W = D² ÷ 162 formula and cross-checked against the tabulated values in BS 4449 and ISO 6935-2. Use these figures to convert a bar bending schedule into shipped tonnage and to estimate container loading.
| Nominal Ø | Mass (kg/m) | Mass per 12 m bar (kg) | Bars per tonne (12 m) | Cross-section (mm²) |
|---|---|---|---|---|
| 8 mm | 0.395 | 4.74 | 211 | 50.3 |
| 10 mm | 0.617 | 7.40 | 135 | 78.5 |
| 12 mm | 0.888 | 10.66 | 94 | 113.1 |
| 14 mm | 1.208 | 14.50 | 69 | 153.9 |
| 16 mm | 1.580 | 18.96 | 53 | 201.1 |
| 18 mm | 2.000 | 24.00 | 42 | 254.5 |
| 20 mm | 2.470 | 29.64 | 34 | 314.2 |
| 22 mm | 2.984 | 35.81 | 28 | 380.1 |
| 25 mm | 3.854 | 46.25 | 22 | 490.9 |
| 28 mm | 4.834 | 58.01 | 17 | 615.8 |
| 32 mm | 6.313 | 75.76 | 13 | 804.2 |
| 36 mm | 7.990 | 95.88 | 10 | 1017.9 |
| 40 mm | 9.864 | 118.37 | 8 | 1256.6 |
Figures are nominal masses based on a steel density of 7,850 kg/m³. Actual delivered mass is governed by the per-bar and per-batch mass tolerances of the certified standard. “Bars per tonne” is rounded down to whole bars for procurement convenience. Need a custom cut length or a bending schedule priced by weight? See cut & bend →
Reinforcement Steel Grades, Side by Side
Specifying across markets means reconciling European, American and ISO grade systems. These cards summarise the characteristic yield, ductility class and typical use for the grades Steel Rebar Germany stocks — so you can match a structural drawing to an export order without guesswork.
B500B
- Characteristic yield (Re)500 MPa
- Ductility classClass B (medium)
- Min. elongation (Agt)5.0%
- Tensile/yield ratio≥1.08
- Typical useGeneral RC frames
B500C
- Characteristic yield (Re)500 MPa
- Ductility classClass C (high)
- Min. elongation (Agt)7.5%
- Tensile/yield ratio1.15–1.35
- Typical useSeismic / high-ductility
Grade 60
- Min. yield420 MPa (60 ksi)
- Min. tensile620 MPa (90 ksi)
- Comparable to≈ B500B yield
- Bar markingSingle line / 60
- Typical useUS / GCC construction
Grade 75
- Min. yield520 MPa (75 ksi)
- Min. tensile690 MPa (100 ksi)
- BenefitReduces congestion
- Bar markingTwo lines / 75
- Typical useColumns, heavy infra
Grade equivalence is approximate and intended for procurement planning, not structural substitution. Always confirm against the project specification and the governing code. Steel Rebar Germany can supply dual-certified bar where a project requires both a BS and an ASTM reference on the same heat — ask the export desk →.
BS, ASTM & ISO Rebar Standards in Plain English
A specification is only as good as the standard it is certified to. Here is what each of the three reference standards Steel Rebar Germany certifies against actually controls — chemistry, mechanical properties, rib geometry and identification.
BS 4449:2005 + A3:2016
Governs weldable ribbed reinforcing steel in grades B500A, B500B and B500C. It fixes the 500 MPa characteristic yield, defines three ductility classes, and specifies rib pattern, bend/rebend performance and the CARES third-party certification regime widely demanded across the UK and GCC.
ASTM A615 / A615M
The standard for deformed and plain carbon-steel bars for concrete reinforcement, covering Grades 40, 60, 75, 80 and 100. It sets minimum yield and tensile strengths, elongation, bend tests and the rolled-in bar marking system (producer, bar size, type and grade) used to identify bar on site.
ISO 6935-2
The ISO reference for ribbed steel for the reinforcement of concrete, harmonising grade designations (e.g. B500B, B500C), nominal mass tolerances, mechanical property limits and bond geometry so that bar can be specified and accepted consistently across international export markets.
BS 8666:2020
The scheduling, dimensioning, bending and cutting standard for steel reinforcement. It defines the shape codes and bending dimensions used on bar bending schedules — the language behind every cut-and-bend order — including minimum bending radii and cutting/bending tolerances.
ISO 9001 & CARES
Beyond the product standard, ISO 9001 certifies the manufacturer’s quality-management system, while CARES (or equivalent) provides independent, audited certification of both the product and the factory production control — the assurance procurement teams look for on certified projects.
The Mill Test Certificate (MTC)
The MTC is the document that ties a delivered bundle back to its heat: chemistry, mechanical results and the certified standard, all keyed to a heat number. Every Steel Rebar Germany shipment ships with a traceable MTC, so conformity can be verified at the port of discharge.
Rebar Specifications & Glossary — 30+ Key Terms
The vocabulary of reinforcement steel, defined for buyers and site teams. From characteristic yield to ribbing to quench-and-self-temper — the terms that appear on drawings, mill certificates and export contracts.
- Rebar
- Reinforcing bar — ribbed steel cast into concrete to carry tensile loads the concrete alone cannot resist.
- TMT Thermo-Mechanically Treated
- Rebar strengthened by rapid surface quenching followed by self-tempering, giving a hard outer ring and a ductile core.
- QST Quench & Self-Temper
- The heat-treatment process behind TMT bar; water-quenches the surface then lets core heat temper it.
- Characteristic Yield (Re)
- The 0.2% proof or yield stress below which no more than 5% of results may fall — the “500” in B500B.
- Tensile Strength (Rm)
- The maximum stress a bar sustains before fracture, always higher than the yield.
- Ductility Class
- A grading (A, B, C in BS/ISO) of how much a bar elongates and work-hardens — critical for seismic design.
- Elongation (Agt)
- Total percentage elongation at maximum force; a key ductility indicator on the MTC.
- Nominal Diameter (Ø)
- The reference bar size (e.g. 16 mm) used for design and weight, distinct from the ribbed outer dimension.
- Nominal Mass
- The standard mass per metre (W = D²/162) used for ordering and tonnage conversion.
- Heat / Cast Number
- The unique ID for a single melt of steel; the anchor of all traceability on the MTC.
- MTC Mill Test Certificate
- The mill’s certified record of chemistry and mechanical properties for a heat of steel.
- Deformations / Ribs
- The transverse ridges rolled onto a bar to develop mechanical bond with concrete.
- Bond / Anchorage
- The grip between bar and concrete that transfers force; governed by rib geometry and embedment length.
- Bar Bending Schedule BBS
- A tabulated list of every bar’s shape, size, length and quantity for a structure, per BS 8666.
- Shape Code
- A BS 8666 number defining a standard bent-bar geometry (e.g. shape 21, an L-bend).
- Cut & Bend
- Factory pre-fabrication of rebar to a bending schedule, reducing on-site labour and offcut waste.
- Stirrup / Link
- A small bent bar that confines longitudinal reinforcement and resists shear in beams and columns.
- Lap Length
- The overlap between two bars needed to transfer force across a splice.
- Cover
- The concrete thickness over the outermost bar that protects it from corrosion and fire.
- Welded Wire Mesh WWM
- A prefabricated grid of welded wires used as area reinforcement in slabs and walls.
- Coil Rebar
- Rebar wound into coils for automated decoiling and cutting at fabrication plants.
- Bend / Rebend Test
- A conformity test bending a sample to confirm ductility and absence of cracking.
- Rib (Relative) Area, fR
- A measure of rib projection controlling bond performance, specified by the standard.
- Weldability / CEV
- Carbon Equivalent Value — a chemistry-based index of how readily a bar can be welded.
- Epoxy-Coated Rebar
- Bar with a fusion-bonded epoxy layer for corrosion resistance in aggressive environments.
- Galvanised Rebar
- Zinc-coated reinforcement offering sacrificial corrosion protection.
- CARES
- UK Certification Authority for Reinforcing Steels — independent product and factory certification.
- Break-Bulk
- Cargo loaded as individual bundles rather than in containers — common for large rebar tonnages.
- Tolerance
- The permitted deviation from nominal mass or dimension under the certified standard.
- Grade (B500B, Gr60)
- The designation combining strength and standard family that defines a bar’s mechanical class.
- Hot-Rolled
- Bar formed at high temperature, giving the ductility and ribbing of standard reinforcement.
- Yield-to-Tensile Ratio
- Rm/Re — a higher ratio signals greater ductility and seismic reserve.
- Decoiling Straightening
- Mechanically uncoiling and straightening coil rebar into cut lengths at a fabrication line.
Rebar Buying & Export Guides
Practical, vendor-neutral guidance for specifying, ordering and importing reinforcement steel — written by our export desk and refreshed as standards and freight conditions change.
How to Read a Mill Test Certificate
Line by line: heat number, chemistry, yield, tensile and elongation — and the red flags that tell you a certificate doesn’t match the bar in front of you.
Read the guide → EstimatingCalculating Rebar Tonnage from a BBS
Turn a bar bending schedule into shipped weight, container counts and a defensible budget — with worked examples using the weight chart above.
Read the guide → SpecifyingB500B vs Grade 60: Which to Specify
When European and American grades are interchangeable, when they aren’t, and how to write a spec that keeps your import clearing customs cleanly.
Read the guide → LogisticsContainer vs Break-Bulk Rebar Shipping
How length, tonnage and destination port determine the most cost-effective way to move rebar — and how to avoid demurrage surprises.
Read the guide → FabricationCut & Bend vs Straight Stock Length
Where pre-fabricated cut-and-bend saves labour and waste, where straight 12 m stock wins, and how BS 8666 shape codes drive the price.
Read the guide → DurabilityPreventing Rebar Corrosion On Site
Cover, coatings and storage practices that protect reinforcement from chloride attack in coastal and Gulf environments.
Read the guide →From Reference to Order
Every spec on this page maps to product we stock and export. Jump straight to the relevant range or talk to the export desk for certified pricing.
Rebar Specification FAQs
How do you calculate the unit weight of rebar per metre?
Use the formula W = D² ÷ 162, where D is the nominal bar diameter in millimetres and W is the mass in kilograms per metre. A 16 mm bar weighs 16² ÷ 162 = 1.580 kg/m. The constant 162 derives from steel’s density (7,850 kg/m³) and unit conversion, and matches the nominal masses tabulated in BS 4449 and ISO 6935-2.
What is the difference between B500B, Grade 60 and Grade 75 rebar?
B500B is the European/British designation (BS 4449, ISO 6935-2) for ribbed bar with a 500 MPa characteristic yield and medium ductility. Grade 60 and Grade 75 are ASTM A615 designations with minimum yields of 60 ksi (≈420 MPa) and 75 ksi (≈520 MPa). B500B and Grade 60 are broadly comparable on yield; Grade 75 is a higher-strength bar that reduces congestion in heavily reinforced members.
What is a Mill Test Certificate (MTC) and why does it matter?
An MTC is the steel mill’s quality document certifying that a heat of rebar meets the ordered standard. It records the heat number, chemistry, mechanical properties and the certified standard. Steel Rebar Germany supplies a heat-traceable MTC with every shipment, so engineers and inspectors can verify conformity to BS 4449, ASTM A615 or ISO 6935 on delivery.
What rebar diameters and lengths does Steel Rebar Germany supply?
We supply hot-rolled ribbed rebar from Ø8 mm to Ø40 mm in standard 12 m stock lengths, with 6 m, 9 m and custom cut lengths available, plus coil for downstream fabrication. Cut-and-bend is produced to BS 8666 shape codes and bar bending schedules. Request a quote →
Spec in Hand? Get Certified Pricing.
Send us your bar bending schedule, grade and destination port. We’ll return a same-day quote with mill-certified rebar — BS 4449, ASTM A615 or ISO 6935, MTC included.
