UK UB and UC Sections — Universal Beam and Column Properties

This reference provides section properties for UK universal beams (UB) and universal columns (UC) rolled to EN 10025-2 standards. These sections are the most commonly used hot-rolled profiles in UK structural steelwork and are the default section types in EN 1993-1-1 design.

All properties shown are for S355 steel (fy = 355 MPa at t <= 16 mm). Design capacities will vary with the actual grade and thickness.

Universal Beams (UB) — Section Properties

Universal beams are primarily used as flexural members (beams) spanning between supports. UB sections are characterised by a high depth-to-width ratio (typically h/b > 1.5).

Designation Mass kg/m Depth h mm Width bf mm Web tw mm Flange tf mm Ix cm4 Wpl,y cm3 A cm2 ry mm
914x419x388 388 920.0 420.5 21.5 36.6 723,000 10,170 493 105
914x305x224 224 910.4 304.1 15.9 23.9 375,000 5,272 286 68.8
838x292x226 226 850.9 293.8 16.1 26.8 339,000 4,896 288 66.2
762x267x197 197 769.8 268.0 15.6 25.4 239,000 3,776 251 61.5
686x254x170 170 692.9 255.8 14.5 23.7 170,000 2,974 217 58.1
610x305x238 238 635.8 311.4 18.4 31.4 162,000 3,254 303 70.6
610x229x140 140 617.2 230.2 13.1 22.1 111,000 2,156 178 50.7
533x210x122 122 544.5 211.9 12.7 21.3 75,900 1,616 156 47.5
533x210x101 101 536.7 209.3 10.8 17.4 61,500 1,286 129 47.5
457x191x98 98 465.1 192.8 11.4 19.6 45,500 1,114 125 43.3
457x191x89 89 463.4 191.9 10.5 17.7 41,000 995 114 43.3
457x152x82 82 465.1 154.4 10.0 18.9 36,400 896 104 35.5
406x178x74 74 412.8 179.6 9.5 16.0 27,300 1,502 94.5 42.2
406x178x60 60 406.4 177.9 7.9 12.8 21,600 1,172 76.4 42.2
356x171x67 67 363.4 173.2 9.1 15.7 17,100 1,043 85.5 40.0
356x127x39 39 352.8 126.0 6.6 10.7 9,170 577 49.8 28.5
305x165x54 54 310.6 166.9 7.9 13.7 11,700 812 68.8 38.5
305x127x48 48 308.7 127.0 8.9 14.5 8,210 613 61.2 29.9
305x102x33 33 312.7 101.9 6.8 10.8 6,480 472 41.7 24.4
254x146x43 43 259.6 147.3 7.2 12.7 6,530 566 55.1 34.7
254x102x28 28 260.4 102.2 6.3 10.0 4,010 354 36.1 24.1
203x133x30 30 206.8 133.9 6.4 9.6 2,900 316 38.2 31.8
203x102x23 23 203.2 101.8 5.4 9.3 2,090 237 29.6 23.7
178x102x19 19 177.7 101.2 4.8 7.9 1,360 176 24.2 23.4
152x89x16 16 152.4 88.7 4.5 7.7 835 124 20.4 20.0
127x76x13 13 127.0 76.0 4.0 7.6 470 80 16.5 17.4

Universal Columns (UC) — Section Properties

Universal columns are primarily used as compression members (columns) and are characterised by a low depth-to-width ratio (typically h/b <= 1.2), providing good buckling resistance about both axes.

Designation Mass kg/m Depth h mm Width bf mm Web tw mm Flange tf mm Ix cm4 Iy cm4 Wpl,y cm3 A cm2 ry mm
356x406x634 634 474.6 424.0 47.6 77.0 287,000 98,200 16,900 808 110
356x406x340 340 425.6 399.0 26.6 42.0 136,000 44,700 7,650 434 101
356x368x202 202 374.7 374.7 16.8 27.0 66,200 23,700 3,911 258 95.8
305x305x283 283 365.3 322.2 26.8 44.1 68,600 24,600 5,040 360 82.6
305x305x198 198 339.9 315.3 19.1 31.4 50,400 16,400 3,421 252 80.7
305x305x137 137 320.5 309.2 13.8 21.7 32,800 10,700 2,188 174 78.4
305x305x97 97 307.8 305.3 9.9 15.4 22,200 7,310 1,481 123 77.0
254x254x167 167 289.1 265.2 19.2 31.7 29,800 9,890 2,623 213 68.1
254x254x132 132 276.3 261.3 15.3 25.3 22,500 7,550 1,946 168 66.9
254x254x107 107 266.7 258.8 12.8 20.5 17,500 5,940 1,496 136 66.0
254x254x89 89 260.3 256.3 10.6 17.3 14,300 4,860 1,214 113 65.5
203x203x86 86 222.2 209.1 12.7 20.5 9,450 3,130 967 110 53.3
203x203x71 71 215.8 206.4 10.3 17.3 7,610 2,540 780 91.1 52.7
203x203x60 60 209.6 205.8 9.4 14.2 6,090 2,070 628 76.4 52.0
203x203x52 52 206.2 204.3 7.9 12.5 5,260 1,780 528 66.4 51.7
203x203x46 46 203.2 203.2 7.2 11.0 4,570 1,540 460 58.8 51.1
152x152x37 37 161.8 154.4 8.0 11.5 2,210 708 314 47.2 38.8
152x152x30 30 157.6 152.9 6.5 9.4 1,750 561 249 38.3 38.2
152x152x23 23 152.4 152.2 5.8 6.8 1,260 400 178 29.5 36.8

Section Selection Guide

Beam Selection (UB)

For simply supported beams, a quick sizing estimate:

Span Approximate UB Size Application
4-6 m 254x146 to 305x165 Floor beams, purlins
6-8 m 356x171 to 406x178 Office floors, roof beams
8-10 m 457x191 to 533x210 Commercial floors, transfer beams
10-15 m 610x229 to 838x292 Long-span roofs, bridge girders
15-20 m 914x305 to 914x419 Heavy industrial, main bridge girders

These estimates assume S355 steel, typical loading (4-7 kN/m2 imposed load), and deflection limit L/250.

Column Selection (UC)

For axially loaded columns (about the minor axis):

Axial Load (kN) Buckling Length 4 m Buckling Length 6 m
500-1000 152x152x23 to 152x152x30 203x203x46 to 203x203x52
1000-2000 203x203x52 to 203x203x71 203x203x60 to 203x203x86
2000-3000 254x254x89 to 254x254x107 254x254x107 to 254x254x132
3000-5000 305x305x97 to 305x305x137 305x305x137 to 305x305x198
5000+ 305x305x198+ or 356x406x340+ 356x406x340+

These estimates assume S355 steel and pinned base connections (effective length factor K = 1.0). Actual capacity depends on combined axial and bending effects, connection fixity, and buckling curve.

Try the Calculator

Use the Beam Capacity Calculator or Column Capacity Calculator to verify section capacities for your specific loading.

Frequently Asked Questions

What is the difference between a UB and a UC section? UB (Universal Beam) has a high depth-to-width ratio (h/b > 1.5) optimised for bending about the major axis. UC (Universal Column) has a low ratio (h/b <= 1.2) providing similar strength about both axes for column buckling resistance. A 406x178x74 UB has h/b = 2.30, while a 203x203x60 UC has h/b = 1.02.

What steel grade are UK sections typically supplied in? UB and UC sections are most commonly stocked in S355J2 per EN 10025-2. S275JR is available for lighter sections and lower-demand applications. S460 is available by special order from most UK stockholders (Barrett Steel, British Steel, Cleveland Steel) but with longer lead times.

How are UK section designations interpreted? The designation follows the format: Depth x Width x Mass per metre - e.g., 406x178x74 UB means 406 mm nominal depth, 178 mm nominal flange width, 74 kg/m mass. The nominal depth is not the exact depth (a 406x178x74 UB has actual depth 412.8 mm). Always use the exact properties from manufacturer data for design calculations.

See Also