The 203 x 203 UC71 universal column is the second-heaviest section in the 203 x 203 range — a genuinely heavy column at 71kg per metre with a 17.3mm flange, used where high axial loads have to be carried within a 203mm footprint. It is specified in multi-storey frames, heavily loaded transfer structures and commercial steelwork where stepping up to a 254 x 254 section would force a redesign of the connections. Rolled to S355J0 and supplied cut free to any length from 1m to 12m in mill finish, with free UK mainland delivery included in the price.
Steel grade — S355J0 to BS EN 10025-2
This column is rolled in S355J0: a 355 N/mm² minimum yield structural steel with impact toughness certified at 0°C. S355 is the grade UK structural engineers design to by default, carrying roughly 29% more yield strength than the older S275 material some merchants still stock. If your engineer has calculated to S275, an S355 section of the same size will always satisfy that design — but never substitute in the opposite direction without going back to them first.
For a fuller comparison see our guide to S275 vs S355 steel, or the steel grades & standards reference for the full specification we supply against.
Near the top of the 203 x 203 range
From the UC60 to the UC71 the flange thickens from 14.2mm to 17.3mm and the web from 9.4mm to 10mm, lifting minor-axis stiffness from 2,064 cm⁴ to 2,537 cm⁴ — a 23% increase. The section grows only slightly, to 215.8 x 206.4mm, so it still sits within the same broad footprint as the rest of the range.
Only the UC86 sits above it at 203 x 203. Beyond that the next move is 254 x 254, which changes the footprint entirely. See UB vs UC, what UK builders actually specify, and the UK steel beam size chart for every size with weights.
Where the UC71 is typically used
Ground-floor columns in three and four-storey steel frames, posts carrying heavily loaded transfer beams, and industrial and commercial structures where a compact but high-capacity column is needed. It is a section that almost always forms part of a fully engineered steel frame rather than a one-off domestic post.
Mill finish
This section is supplied in mill finish — bare structural steel exactly as it leaves the rolling mill, carrying the usual blue-grey mill scale. It suits any job where the column will be encased, boxed in, fire-protected or painted on site — see our guide to boxing in steelwork, or whether structural steel needs painting at all. Store it dry and ventilated, and protect it with a suitable coating system if it will be exposed or used externally.
Cut to size — free, to the millimetre
Tell us the length you need and we cut it. There is no charge for cutting and no minimum order beyond a single metre. Enter your dimensions in the calculator above — you can specify several cut lengths on one order and the tool works out what you need. Steel is supplied and billed in whole metres, so a 2.7m requirement is charged as 3m; where you order more than one cut, the total is rounded once rather than cut by cut.
Cut tolerance is ±3mm on length. Tell us if your head detail is critical, and confirm the base plate, padstone and holding-down bolt arrangement with your engineer before ordering. More on what lengths structural steel comes in.
Section dimensions
| Depth of section (h) | 215.8 mm |
| Width of section (b) | 206.4 mm |
| Web thickness (s) | 10.0 mm |
| Flange thickness (t) | 17.3 mm |
| Root radius (r) | 10.0 mm |
| Depth between fillets (d) | 161.2 mm |
| Mass per metre | 71.0 kg/m |
| Cross-sectional area | 90.4 cm² |
| Surface area per metre | 1.220 m²/m |
Section properties
| Second moment of area, y-y (Iy) | 7,615 cm⁴ |
| Second moment of area, z-z (Iz) | 2,537 cm⁴ |
| Elastic modulus, y-y (Wel,y) | 705.7 cm³ |
| Elastic modulus, z-z (Wel,z) | 245.8 cm³ |
| Plastic modulus, y-y (Wpl,y) | 798.4 cm³ |
| Plastic modulus, z-z (Wpl,z) | 373.6 cm³ |
| Radius of gyration, y-y (iy) | 9.1 cm |
| Radius of gyration, z-z (iz) | 5.2 cm |
Nominal dimensions and properties to BS EN 10365. Figures are published for reference only.
Structural engineer notice
Column sizing cannot be taken from a table. Capacity depends on the axial load, the effective length between restraints, the end fixity, any bending applied at the connections, and the base and head details — all of which must be calculated by a qualified structural engineer, and in most cases will form part of your building control submission. Base plates, padstones and holding-down bolts are part of that design. We supply steel to the specification you give us; we do not provide structural design.
Delivery — plan the lift
Cut-to-size steel is dispatched on a 5–10 working day lead time, with free delivery to UK mainland addresses included in the price — no carriage is added at checkout. At 71kg per metre a 3m post is 213kg and a 5m post is 355kg. Deliveries are kerbside and offloading assistance is required — mechanical lifting is essential at this weight. See how structural steel is delivered, or our delivery & lead times page. Ordering a full frame? Trade discounts are available.
Related sections
- 203 x 203 UC60 steel column — lighter section in the same serial size
- 203 x 203 UC86 steel column — heaviest in the same serial size
- 254 x 254 UC73 steel column — larger footprint for the highest loads
- All universal columns (UC)
- All RSJ steel beams & columns