StructureCalcs203x133x25 UB
Universal Beam · BS 4-1 · United Kingdom
203x133x25 UB is a British universal beam 203.2 mm deep with a 133.2 mm wide flange, weighing 25.1 kg/m. The dimensions below are the published BS 4-1 values; the drawing is generated from them.
British Universal Beams to BS 4-1 are the UK’s standard I-beam — the same designation style as the Australian UB, but a distinct dimension table.
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Published dimensions
| Property | Metric | Imperial |
|---|---|---|
| Depth, d | 203.2 mm | 8.00 in |
| Flange width, bf | 133.2 mm | 5.24 in |
| Flange thickness, tf | 7.8 mm | 0.307 in |
| Web thickness, tw | 5.7 mm | 0.224 in |
| Mass per metre | 25.1 kg/m | 16.9 lb/ft |
| Area, A | 3,200 mm² | 4.96 in² |
| Second moment, Ix | 23,400,000 mm⁴ | 56.2 in⁴ |
| Second moment, Iy | 3,080,000 mm⁴ | 7.4 in⁴ |
Derived section properties
Integrated from the section's own outline including the root and toe radii, whose arcs are integrated analytically rather than approximated by facets. For 203x133x25 UB the computed area agrees with the published value to 0.02% and Ix to 0.10%. Where a value is also published, the published one above is the one to quote.
| Property | Value |
|---|---|
| Elastic modulus, Zx | 230,548 mm³ |
| Elastic modulus, Zy | 46,192 mm³ |
| Plastic modulus, Sx | 257,972 mm³ |
| Plastic modulus, Sy | 70,958 mm³ |
| Radius of gyration, rx | 85.6 mm |
| Radius of gyration, ry | 31.0 mm |
Z is the elastic modulus and S the plastic modulus, following British practice (BS 5950 notation). Under AISC 360 the letters are reversed.
Neighbouring sizes
Where these numbers come from
Published BS 4-1 values. How StructureCalcs verifies its numbers · Understanding steel section properties · Query this section over the API