RIBBED BARS

Reinforcing steel bars, universally known as rebar, are the essential steel component in reinforced concrete construction. ULAMEX supplies high-ductility B500B reinforcing bar in diameters from 6 mm to 32 mm, manufactured from weldable reinforcing steel with a characteristic ribbed surface pattern engineered to maximise bond strength with concrete. Our rebar is produced in full compliance with EN 10080 and delivered in standard lengths of 6,000 mm and 12,000 mm, with a professional cut-and-bent service available for projects requiring pre-fabricated reinforcement shapes. With over 38 years of experience as a reinforcing steel supplier, ULAMEX maintains comprehensive stock of the most specified rebar sizes for immediate dispatch to construction sites across the United Kingdom, Scandinavia, Benelux and the wider European market.

Material Grade and Standards for Reinforcing Steel

Our reinforcing steel bars are manufactured exclusively in grade B500B, the standard weldable reinforcing steel grade specified across the majority of European structural concrete designs. The “B” in B500B denotes high ductility (class B per EN 1992-1-1 / Eurocode 2), providing the deformation capacity required for seismic design, redistribution of bending moments and plastic analysis of reinforced concrete structures. Key material properties of B500B reinforcing steel include:

• Characteristic yield strength (f_yk): 500 MPa
• Tensile-to-yield ratio (f_t/f_y): ≥ 1.08 (ensuring strain hardening before failure)
• Elongation at maximum force (A_gt): ≥ 5.0% (high ductility class B)
• Carbon equivalent (C_eq): ≤ 0.50% (guaranteeing weldability per EN ISO 17660)

Production and testing of our rebar comply with EN 10080 (steel for the reinforcement of concrete — weldable reinforcing steel), supplemented by national application standards as required. Welding of reinforcing steel connections — including lap joints, cruciform joints and end-to-end butt welds — is governed by EN ISO 17660-1 (load-bearing welds) and EN ISO 17660-2 (non-load-bearing welds). All welding must be performed by certified welders using qualified welding procedures appropriate to the bar diameter and joint configuration.

For projects where full material traceability is mandated, we supply EN 10204 Type 3.1 inspection certificates confirming chemical composition, mechanical test results and rib geometry compliance. Each bar carries a rolling mark identifying the producer, steel grade and country of origin in accordance with EN 10080 Annex B.

Dimensions, Sizes and Specifications

ULAMEX stocks rebar sizes across the full range specified in European reinforced concrete design:

• Nominal diameter range: 6, 8, 10, 12, 14, 16, 20, 25, 28, and 32 mm
• Standard lengths: 6,000 mm (6 m) and 12,000 mm (12 m)
• Surface pattern: hot rolled ribbed (deformed) surface to EN 10080
• Cross-sectional area (nominal): from 28.3 mm² (diameter 6) to 804.2 mm² (diameter 32)

The ribbed surface profile of deformed steel bar consists of transverse ribs and longitudinal ribs rolled into the bar during production. The rib geometry — including rib height, rib spacing and rib inclination angle — is specified by EN 10080 to achieve a minimum relative rib area (f_R) that ensures adequate bond performance with concrete. For B500B bars, the minimum relative rib area ranges from 0.035 (for diameter 6) to 0.056 (for diameters ≥ 12 mm).

The weight per metre of reinforcing steel bar follows the formula: diameter² × 0.006165 kg/m. For the most common sizes: 8 mm rebar weighs 0.395 kg/m, 10 mm rebar weighs 0.617 kg/m, 12 mm rebar weighs 0.888 kg/m, 16 mm rebar weighs 1.578 kg/m, 20 mm rebar weighs 2.466 kg/m, 25 mm rebar weighs 3.853 kg/m, and 32 mm rebar weighs 6.313 kg/m. Dimensional tolerances on nominal diameter conform to EN 10080, with mass per metre tolerances of ±4.5% for individual bars and ±3.0% for batch averages.

Applications of Reinforcing Steel Bars

Rebar is used in virtually every type of reinforced concrete structure worldwide. The ribbed surface creates a mechanical interlock with the surrounding concrete, allowing the composite material to resist both compressive forces (carried by the concrete) and tensile forces (carried by the steel reinforcement). Principal application areas include:

• Foundations and ground works — strip foundations, pad foundations, raft foundations and piled foundations. Reinforcing bar in diameters 12–25 mm forms the primary reinforcement in foundation slabs, while 8–10 mm bars are used for distribution reinforcement and anti-crack mesh replacement.
• Slabs and floors — suspended floor slabs, ground-bearing slabs, roof slabs and composite floor decks. The most commonly specified diameters for slab reinforcement are 10, 12 and 16 mm, typically at 150–200 mm centres in both directions.
• Columns and walls — vertical reinforcement in reinforced concrete columns, shear walls, retaining walls and core walls of multi-storey buildings. Columns typically require 16–32 mm bars as main reinforcement with 8–10 mm links (stirrups) for shear and confinement.
• Beams and lintels — main tensile reinforcement in floor beams, transfer beams, ring beams and door/window lintels. Beam reinforcement commonly uses 16–25 mm bars in the tension zone with 8–12 mm shear links.
• Infrastructure and civil engineering — bridge decks, tunnel linings, culverts, retaining structures, sea walls and highway barriers. Infrastructure projects frequently specify 20–32 mm deformed steel bars for heavily loaded elements.
• Precast concrete — reinforcement cages for precast beams, columns, wall panels, staircases and pipe segments. Cut-and-bent rebar in pre-fabricated cage assemblies significantly accelerates precast production.

For projects requiring pre-shaped reinforcement, ULAMEX offers a professional cut-and-bent service. Bars are cut to specified lengths and bent to required shapes (cranks, hooks, U-bars, L-bars, stirrups) in accordance with BS 8666 shape codes or equivalent European scheduling standards, ready for direct installation on site without further processing.

Technical Properties of Reinforcing Steel

The mechanical and physical properties of B500B reinforcing steel are specifically designed for optimal performance in reinforced concrete structures:

• Characteristic yield strength (f_yk): 500 MPa
• Characteristic tensile strength: ≥ 540 MPa (f_t/f_y ≥ 1.08)
• Elongation at maximum force (A_gt): ≥ 5.0%
• Density: 7,850 kg/m³
• Modulus of elasticity: 200,000 MPa (200 GPa, as assumed in Eurocode 2)
• Thermal expansion coefficient: 10 × 10⁻⁶ /°C (compatible with concrete)
• Fatigue strength: 2 million cycles at stress range per EN 10080 Annex C

Weldability is a defining characteristic of B500B grade reinforcing steel. The controlled chemical composition — with carbon equivalent (C_eq) limited to 0.50% and carbon content not exceeding 0.22% — ensures reliable weldability for both load-bearing and non-load-bearing connections per EN ISO 17660. Common welding methods include flash butt welding (for end-to-end joints in large-diameter bars), manual metal arc welding and friction welding. Preheat is generally not required for bar diameters up to 25 mm under normal ambient conditions.

The bond between ribbed reinforcing bars and concrete is quantified by the bond strength coefficient, which for B500B bars with compliant rib geometry exceeds 2.25 times that of plain (smooth) bars of equivalent diameter. This superior bond performance allows engineers to design shorter anchorage and lap lengths, reducing reinforcement quantities and simplifying congested reinforcement details.

Quality Assurance and Certification

ULAMEX operates under EN 1090-1 factory production control and ISO 3834-2 quality management. Our reinforcing steel bars are sourced exclusively from CE-marked producers operating under EN 10080 factory production control certification. Each production batch is tested for yield strength, tensile strength, elongation, bend and rebend performance, and rib geometry. We provide EN 10204 Type 3.1 inspection certificates on request, and all bars carry rolling marks for full traceability. Our certifications assure contractors, structural engineers and main contractors that every bar meets the performance requirements of Eurocode 2 and the relevant national annexes.

Ordering and Delivery

The most popular rebar sizes in both 6 m and 12 m lengths are maintained in stock for rapid despatch. Standard lead time for stock items is 2–5 working days across Europe. For cut-and-bent reinforcement, we process orders against bar bending schedules with typical turnaround times of 5–10 working days depending on project complexity. Large project quantities can be delivered direct from the mill with competitive lead times. All reinforcing bars are bundled, tagged with bar mark references and accompanied by delivery documentation for site checking against the bending schedule.

To request a quotation for reinforcing steel bars, rebar, cut-and-bent reinforcement or any product from our black steel rods range, please contact our sales team. We provide expert technical advice, competitive wholesale pricing and reliable delivery logistics across the United Kingdom, Scandinavia, Benelux and the wider European market — backed by more than 35 years of steel distribution experience.