Hot-rolled C-channels in UPN designation are among the most versatile and widely specified structural steel sections in European construction, mechanical engineering and general fabrication. Produced by hot rolling in accordance with EN 10365, UPN steel channels feature the characteristic U-shaped cross-section with tapered flanges that has been a fundamental building block of steel construction for over a century. ULAMEX stocks the complete range of UPN channels from UPN 50 to UPN 400 in S235JR and S355J2 structural steel grades, available in standard lengths of 6,000 mm and 12,000 mm for immediate dispatch across Europe. As a specialist steel sections supplier with over 35 years of market experience, we deliver hot-rolled channels for projects ranging from single-unit fabrication shops to large-scale industrial construction sites.
Material Grades and Standards for Hot-Rolled UPN Channels
All hot-rolled C-channels supplied by ULAMEX are manufactured from non-alloy structural steel per EN 10025-2, the definitive European standard for hot rolled steel products. Our stock programme includes two grades that together cover the requirements of over 95% of channel applications in construction and industry:
- S235JR (material number 1.0038, formerly St37-2, international equivalent ASTM A36) — the universal mild steel grade for general-purpose structural and fabrication work. With a minimum yield strength of 235 MPa (thicknesses to 16 mm), tensile strength of 360–510 MPa, minimum elongation of 26% and guaranteed impact toughness of 27 J at +20°C (JR designation), S235JR channels are the standard choice for bracing systems, secondary framing, support brackets and general connections. The carbon content is limited to a maximum of 0.17% (for product thicknesses up to 16 mm), contributing to excellent weldability.
- S355J2 (material number 1.0577, formerly St52-3, comparable to ASTM A572 Grade 50) — a higher-performance grade delivering a minimum yield strength of 355 MPa, tensile strength of 470–630 MPa, minimum elongation of 22% and crucially, guaranteed impact toughness of 27 J at -20°C (J2 designation). S355J2 steel UPN channels are specified for crane rail supporting structures, bridge cross-bracing, heavy-duty platform construction and any application requiring superior strength or low-temperature service capability. The approximately 50% higher yield strength compared to S235JR allows designers to use smaller profile sizes, saving weight and cost.
For both grades, the chemical composition and mechanical properties are fully compliant with EN 10025-2, and CE marking is provided per EN 10025-1 in accordance with the Construction Products Regulation (CPR).
Dimensions, Sizes and Specifications of UPN Steel Channels
Our hot-rolled UPN channels are produced in accordance with EN 10365 (which superseded the former EN 10279 for designation purposes) and cover the full standard dimensional range. The defining feature of UPN channels is their tapered flanges — the inner flange surfaces slope at approximately 8% (a taper of about 5°), which provides increased flange thickness at the root junction with the web. This geometry enhances local stiffness and resistance to concentrated loads at the web-flange intersection.
Available steel channel sizes in our stock programme:
- UPN 50 (50 mm height, 38 mm flange width, 5.0 mm web thickness, 5.59 kg/m)
- UPN 65, UPN 80 (8.64 kg/m), UPN 100 (10.6 kg/m)
- UPN 120 (13.4 kg/m), UPN 140 (16.0 kg/m), UPN 160 (18.8 kg/m)
- UPN 180 (22.0 kg/m), UPN 200 (25.3 kg/m), UPN 220 (29.4 kg/m)
- UPN 240 (33.2 kg/m), UPN 260 (37.9 kg/m), UPN 280 (41.8 kg/m)
- UPN 300 (46.2 kg/m), UPN 320, UPN 350, UPN 380, UPN 400 (71.8 kg/m)
Standard lengths of 6,000 mm and 12,000 mm are held in stock. Dimensional and shape tolerances comply with EN 10279. The surface finish is hot rolled mill scale as delivered from the rolling mill. Cut-to-size sawing to custom lengths is available on request.
Applications of Hot-Rolled UPN Steel Channels
The robust cross-section and excellent structural properties of UPN channels make them indispensable across a wide range of construction and engineering disciplines. The tapered flanges provide inherent local stiffness, while the U-shape offers efficient load transfer in multiple orientations:
- Steel frame construction and bracing systems — UPN channels are used extensively as cross-bracing members, horizontal stiffeners and wind bracing in steel-framed buildings and industrial halls. Paired back-to-back, two UPN channels form a symmetrical I-section that can serve as columns or beams where standard IPE or HEB profiles are not suitable. This versatile configuration is common in industrial hall construction and portal frame buildings.
- Bridge construction and infrastructure — In bridge engineering, UPN channels serve as transverse floor beams, lateral bracing members and stiffening ribs for plate girders. The S355J2 grade with its guaranteed -20°C impact toughness is preferred for exposed bridge applications subject to low-temperature service conditions.
- Crane rail systems and runway beams — UPN channels act as rail support beams, guide channels for crane wheels and lateral restraint members for overhead crane runway structures. Their dimensional consistency ensures smooth crane travel and predictable load distribution.
- Platform, stairway and access construction — Industrial platforms, mezzanine edge beams, stairway stringers and handrail posts frequently utilise UPN channels due to their straightforward connection detailing and reliable load-bearing performance.
- Vehicle and trailer construction — The chassis frames of trailers, agricultural equipment and special vehicles often incorporate UPN channels as longitudinal and cross-members due to their excellent bending stiffness and shear resistance.
- General fabrication and machine frames — From welded machine bases and conveyor supports to gate frames and fence posts, hot rolled steel channels provide a cost-effective structural element for countless fabrication applications.
- Composite sections and built-up members — UPN channels are frequently welded or bolted together with flat bars, angles or plates to create custom cross-sections for specific load requirements, such as compound beams, box columns or reinforced edge members.
Technical Properties of Hot-Rolled UPN Channels
The hot rolling manufacturing process and the specific cross-sectional geometry of UPN channels deliver a set of technical properties well suited to demanding structural applications:
- Weldability — Both S235JR and S355J2 UPN channels are fully weldable using all standard arc welding processes including MIG/MAG, TIG, MMA (stick) and submerged arc welding (SAW). For thicknesses above 25 mm, preheat temperatures should be determined from the carbon equivalent value (CEV) per EN 1011-2. The tapered flange geometry requires careful weld preparation when making flange-to-flange or flange-to-plate connections to ensure full penetration.
- Machinability — UPN channels can be drilled, punched, sawn, flame-cut and plasma-cut with standard steel fabrication equipment. The tapered flanges require consideration when drilling bolt holes, as standard flat-bottomed drilling may require flange preparation or use of tapered washers to ensure proper bolt seating.
- Surface treatment and corrosion protection — As-delivered mill scale surface is suitable for indoor applications. For external or aggressive environments, preparation by blast cleaning to Sa 2½ per ISO 8501-1 followed by a primer and topcoat paint system provides effective corrosion protection. Hot-dip galvanising per EN ISO 1461 is widely used for exposed structural channels. The internal surfaces of the U-profile should receive particular attention during coating to prevent moisture trapping.
- Structural behaviour — UPN channels are non-symmetrical sections (the shear centre lies outside the cross-section), which means they are susceptible to lateral-torsional buckling under certain loading conditions. Structural engineers must account for this in beam design per Eurocode 3 (EN 1993-1-1) by providing adequate lateral restraint or using paired channels to form a symmetric section.
Quality Assurance and Certification for UPN Channels
ULAMEX is an EN 1090 certified steel distributor with full compliance under the European Construction Products Regulation (CPR). Our ISO 3834-2 quality management system ensures consistent processes across the entire supply chain — from raw material procurement and supplier qualification through warehouse storage, handling and final delivery. Material traceability is maintained to the originating steel mill and individual production heat for every UPN channel in stock. Mill test certificate 3.1 per EN 10204 is available on request, documenting the chemical composition, mechanical properties and test results for the specific heat from which your channels were produced.
Ordering UPN Channels — Stock, Delivery and Wholesale Terms
As a focused structural steel supplier and steel wholesale partner, ULAMEX keeps the most frequently specified UPN channel sizes in both S235JR and S355J2 grades permanently in stock. Standard profiles are available for immediate dispatch, with delivery across Western and Central Europe typically within 3–5 working days. Sawing to custom lengths is available for all channel sizes — simply include your required dimensions in your enquiry. For large project quantities, direct mill orders offer competitive lead times and volume-based wholesale conditions.
Compare our hot-rolled UPN channels with the cold-formed UPE alternatives in our full steel sections catalogue. Whether you need a single bundle of UPN 120 for a workshop project or containerloads of mixed channels for an infrastructure programme, our steel sections team will prepare a detailed quotation with competitive pricing. Request a quote today and experience the reliability and service quality that over 35 years in the steel distribution business have built.