Steel Beam Size Chart (UK): UB, UC & PFC Sizes and Weights

Stacked universal steel beams (UB) and columns on a UK steel stockholder rack

This free UK steel beam size chart lists every standard Universal Beam (UB), Universal Column (UC) and Parallel Flange Channel (PFC) section, with full dimensions and section properties — depth, width, web and flange thickness, mass per metre, cross-sectional area, second moment of area and elastic section modulus. Every section is designated by three numbers, depth × width × mass per metre, so a 203 × 133 × 25 UB is nominally 203mm deep, 133mm wide and 25kg/m. All sections are to BS EN 10365, commonly supplied in S355 (S275 vs S355) — see our steel grades & standards.

For an indicative beam size and weight for your opening, use the RSJ beam size guide and calculator. New to the terms? Start with what is an RSJ?

Reference only: Dimensions and section properties are nominal values to BS EN 10365, cross-checked against the SCI P363 “Blue Book”. This chart is a planning and reference tool and is not a substitute for a structural engineer’s design. Never specify or order a beam for a structural opening without engineer sign-off.

How to Read a Steel Beam Size

A section such as 254 × 146 × 37 UB means nominal depth 254mm, nominal flange width 146mm and mass 37kg/m. A UB is deeper than it is wide (spans openings); a UC is roughly square (columns and posts); a PFC is a C-shaped channel (lintels and edge beams).

UB vs UC vs PFC vs Box Section

Section Shape Typical use
Universal Beam (UB) Deep I-section Spanning horizontal openings — beams and lintels
Universal Column (UC) Near-square H-section Columns and posts carrying vertical load
Parallel Flange Channel (PFC) C-shaped channel Lintels, trimmers and edge beams with a flat back
Box section (SHS / RHS) Hollow square / rectangle Frames, posts and exposed structural steel

Universal Beam (UB) Sizes & Properties

Universal beams — also called RSJs, steel I-beams or steel girders — span horizontal openings. The full standard UK range to BS EN 10365 is below.

Reading the properties: values are about the major (y-y) axis. I = second moment of area (cm4); Wel = elastic section modulus (cm3); Area in cm2. Minor-axis (z-z) and plastic properties to BS EN 10365 are available on request. The column headings stay in view as you scroll the table.
Section Depth h (mm) Width b (mm) Web s (mm) Flange t (mm) Mass (kg/m) Area (cm²) I y-y (cm⁴) Wel y-y (cm³)
127 x 76 x 13 UB 127 76 4 7.6 13 16.5 473 74.6
152 x 89 x 16 UB 152.4 88.7 4.5 7.7 16 20.3 834 109
178 x 102 x 19 UB 177.8 101.2 4.8 7.9 19 24.3 1,360 153
203 x 102 x 23 UB 203.2 101.8 5.4 9.3 23.1 29.4 2,100 207
203 x 133 x 25 UB 203.2 133.2 5.7 7.8 25.1 32 2,340 230
203 x 133 x 30 UB 206.8 133.9 6.4 9.6 30 38.2 2,900 280
254 x 146 x 31 UB 251.4 146.1 6 8.6 31.1 39.7 4,410 351
254 x 102 x 22 UB 254 101.6 5.7 6.8 22 28 2,840 224
254 x 146 x 37 UB 256 146.4 6.3 10.9 37 47.2 5,540 433
254 x 102 x 25 UB 257.2 101.9 6 8.4 25.2 32 3,410 266
254 x 146 x 43 UB 259.6 147.3 7.2 12.7 43 54.8 6,540 504
254 x 102 x 28 UB 260.4 102.2 6.3 10 28.3 36.1 4,000 308
305 x 165 x 40 UB 303.4 165 6 10.2 40.3 51.3 8,500 560
305 x 127 x 37 UB 304.4 123.4 7.1 10.7 37 47.2 7,170 471
305 x 102 x 25 UB 305.1 101.6 5.8 7 24.8 31.6 4,460 292
305 x 165 x 46 UB 306.6 165.7 6.7 11.8 46.1 58.7 9,900 646
305 x 127 x 42 UB 307.2 124.3 8 12.1 41.9 53.4 8,200 534
305 x 102 x 28 UB 308.7 101.8 6 8.8 28.2 35.9 5,370 348
305 x 165 x 54 UB 310.4 166.9 7.9 13.7 54 68.8 11,700 754
305 x 127 x 48 UB 311 125.3 9 14 48.1 61.2 9,570 616
305 x 102 x 33 UB 312.7 102.4 6.6 10.8 32.8 41.8 6,500 416
356 x 127 x 33 UB 349 125.4 6 8.5 33.1 42.1 8,250 473
356 x 171 x 45 UB 351.4 171.1 7 9.7 45 57.3 12,100 687
356 x 127 x 39 UB 353.4 126 6.6 10.7 39.1 49.8 10,200 576
356 x 171 x 51 UB 355 171.5 7.4 11.5 51 64.9 14,100 796
356 x 171 x 57 UB 358 172.2 8.1 13 57 72.6 16,000 896
356 x 171 x 67 UB 363.4 173.2 9.1 15.7 67.1 85.5 19,500 1,070
406 x 140 x 39 UB 398 141.8 6.4 8.6 39 49.7 12,500 629
406 x 178 x 54 UB 402.6 177.7 7.7 10.9 54.1 69 18,700 930
406 x 140 x 46 UB 403.2 142.2 6.8 11.2 46 58.6 15,700 778
406 x 178 x 60 UB 406.4 177.9 7.9 12.8 60.1 76.5 21,600 1,060
406 x 140 x 53 UB 406.6 143.3 7.9 12.9 53.3 67.9 18,300 899
406 x 178 x 67 UB 409.4 178.8 8.8 14.3 67.1 85.5 24,300 1,190
406 x 178 x 74 UB 412.8 179.5 9.5 16 74.2 94.5 27,300 1,320
457 x 152 x 52 UB 449.8 152.4 7.6 10.9 52.3 66.6 21,400 950
457 x 191 x 67 UB 453.4 189.9 8.5 12.7 67.1 85.5 29,400 1,300
457 x 152 x 60 UB 454.6 152.9 8.1 13.3 59.8 76.2 25,500 1,120
457 x 191 x 74 UB 457 190.4 9 14.5 74.3 94.6 33,300 1,460
457 x 152 x 67 UB 458 153.8 9 15 67.2 85.6 28,900 1,260
457 x 191 x 82 UB 460 191.3 9.9 16 82 104 37,100 1,610
457 x 152 x 74 UB 462 154.4 9.6 17 74.2 94.5 32,700 1,410
457 x 191 x 89 UB 463.4 191.9 10.5 17.7 89.3 114 41,000 1,770
457 x 152 x 82 UB 465.8 155.3 10.5 18.9 82.1 105 36,600 1,570
457 x 191 x 98 UB 467.2 192.8 11.4 19.6 98.3 125 45,700 1,960
533 x 210 x 82 UB 528.3 208.8 9.6 13.2 82.2 105 47,500 1,800
533 x 210 x 92 UB 533.1 209.3 10.1 15.6 92.1 117 55,200 2,070
533 x 210 x 101 UB 536.7 210 10.8 17.4 101 129 61,500 2,290
533 x 210 x 109 UB 539.5 210.8 11.6 18.8 109 139 66,800 2,480
533 x 210 x 122 UB 544.5 211.9 12.7 21.3 122 155 76,000 2,790
610 x 229 x 101 UB 602.6 227.6 10.5 14.8 101.2 129 75,800 2,520
610 x 229 x 113 UB 607.6 228.2 11.1 17.3 113 144 87,300 2,870
610 x 229 x 125 UB 612.2 229 11.9 19.6 125.1 159 98,600 3,220
610 x 305 x 149 UB 612.4 304.8 11.8 19.7 149.2 190 126,000 4,110
610 x 229 x 140 UB 617.2 230.2 13.1 22.1 139.9 178 112,000 3,620
610 x 305 x 179 UB 620.2 307.1 14.1 23.6 179 228 153,000 4,930
610 x 305 x 238 UB 635.8 311.4 18.4 31.4 238.1 303 209,000 6,590
686 x 254 x 125 UB 677.9 253 11.7 16.2 125.2 159 118,000 3,480
686 x 254 x 140 UB 683.5 253.7 12.4 19 140.1 178 136,000 3,990
686 x 254 x 152 UB 687.5 254.5 13.2 21 152.4 194 150,000 4,370
686 x 254 x 170 UB 692.9 255.8 14.5 23.7 170.2 217 170,000 4,920
762 x 267 x 134 UB 750 264.4 12 15.5 133.9 171 151,000 4,020
762 x 267 x 147 UB 754 265.2 12.8 17.5 146.9 187 169,000 4,470
762 x 267 x 173 UB 762.2 266.7 14.3 21.6 173 220 205,000 5,390
762 x 267 x 197 UB 769.8 268 15.6 25.4 196.8 251 240,000 6,230
838 x 292 x 176 UB 834.9 291.7 14 18.8 175.9 224 246,000 5,890
838 x 292 x 194 UB 840.7 292.4 14.7 21.7 193.8 247 279,000 6,640
838 x 292 x 226 UB 850.9 293.8 16.1 26.8 226.5 289 340,000 7,980
914 x 305 x 201 UB 903 303.3 15.1 20.2 200.9 256 325,000 7,200
914 x 305 x 224 UB 910.4 304.1 15.9 23.9 224.2 286 376,000 8,270
914 x 305 x 253 UB 918.4 305.5 17.3 27.9 253.4 323 436,000 9,500
914 x 305 x 289 UB 926.6 307.7 19.5 32 289.1 368 504,000 10,900
914 x 419 x 343 UB 911.8 418.5 19.4 32 343.3 437 626,000 13,700
914 x 419 x 388 UB 921 420.5 21.4 36.6 388 494 720,000 15,600
1016 x 305 x 222 UB 970.3 300 16 21.1 222 283 408,000 8,410
1016 x 305 x 249 UB 980.1 300 16.5 26 248.7 317 481,000 9,820
1016 x 305 x 314 UB 999.9 300 19.1 35.9 314.3 400 644,000 12,900
1016 x 305 x 393 UB 1,015.9 303 24.4 43.9 392.7 500 808,000 15,900
1016 x 305 x 438 UB 1,026 305 26.9 49 438 556 910,000 17,700
1016 x 305 x 494 UB 1,036 309 31 54 494 629 1,028,000 19,800
1016 x 305 x 584 UB 1,056 314 36 64 584 744 1,246,000 23,600

Universal Column (UC) Sizes & Properties

Universal columns are near-square sections carrying vertical load as posts and columns — see UB vs UC.

Section Depth h (mm) Width b (mm) Web s (mm) Flange t (mm) Mass (kg/m) Area (cm²) I y-y (cm⁴) Wel y-y (cm³)
152 x 152 x 23 UC 152.4 152.2 5.8 6.8 23 29.2 1,250 164
152 x 152 x 30 UC 157.6 152.9 6.5 9.4 30 38.3 1,750 222
152 x 152 x 37 UC 161.8 154.4 8 11.5 37 47.1 2,210 273
152 x 152 x 44 UC 166 155.9 9.5 13.6 44 56.1 2,700 326
152 x 152 x 51 UC 170.2 157.4 11 15.7 51.2 65.2 3,230 379
203 x 203 x 46 UC 203.2 203.6 7.2 11 46.1 58.7 4,570 450
203 x 203 x 52 UC 206.2 204.3 7.9 12.5 52 66.3 5,260 510
203 x 203 x 60 UC 209.6 205.8 9.4 14.2 60 76.4 6,120 584
203 x 203 x 71 UC 215.8 206.4 10 17.3 71 90.4 7,620 706
203 x 203 x 86 UC 222.2 209.1 12.7 20.5 86.1 110 9,450 850
203 x 203 x 100 UC 228.6 210.3 14.5 23.7 99.6 127 11,300 988
203 x 203 x 113 UC 235 212.1 16.3 26.9 113.5 145 13,300 1,130
203 x 203 x 127 UC 241.4 213.9 18.1 30.1 127.5 162 15,400 1,280
254 x 254 x 73 UC 254.1 254.6 8.6 14.2 73.1 93.1 11,400 898
254 x 254 x 89 UC 260.3 256.3 10.3 17.3 88.9 113 14,300 1,100
254 x 254 x 107 UC 266.7 258.8 12.8 20.5 107.1 136 17,500 1,310
254 x 254 x 132 UC 276.3 261.3 15.3 25.3 132 168 22,500 1,630
254 x 254 x 167 UC 289.1 265.2 19.2 31.7 167.1 213 30,000 2,080
305 x 305 x 97 UC 307.9 305.3 9.9 15.4 96.9 123 22,200 1,450
305 x 305 x 118 UC 314.5 307.4 12 18.7 117.9 150 27,700 1,760
305 x 305 x 137 UC 320.5 309.2 13.8 21.7 136.9 174 32,800 2,050
305 x 305 x 158 UC 327.1 311.2 15.8 25 158.1 201 38,700 2,370
305 x 305 x 198 UC 339.9 314.5 19.1 31.4 198.1 252 50,900 3,000
305 x 305 x 240 UC 352.5 318.4 23 37.7 240 306 64,200 3,640
305 x 305 x 283 UC 365.3 322.2 26.8 44.1 282.9 360 78,900 4,320
356 x 368 x 129 UC 355.6 368.6 10.4 17.5 129 164 40,200 2,260
356 x 368 x 153 UC 362 370.5 12.3 20.7 152.9 195 48,600 2,680
356 x 368 x 177 UC 368.2 372.6 14.4 23.8 177 226 57,100 3,100
356 x 368 x 202 UC 374.6 374.7 16.5 27 201.9 257 66,300 3,540
356 x 406 x 235 UC 381 394.8 18.4 30.2 235.1 299 79,100 4,150
356 x 406 x 287 UC 393.6 399 22.6 36.5 287.1 366 99,900 5,070
356 x 406 x 340 UC 406.4 403 26.6 42.9 339.9 433 123,000 6,030
356 x 406 x 393 UC 419 407 30.6 49.2 393 501 147,000 7,000
356 x 406 x 467 UC 436.6 412.2 35.8 58 467 595 183,000 8,380
356 x 406 x 551 UC 455.6 418.5 42.1 67.5 551 702 227,000 9,960
356 x 406 x 634 UC 474.6 424 47.6 77 633.9 808 275,000 11,600

Parallel Flange Channel (PFC) Sizes & Properties

PFC channels are used as lintels, trimmers and edge beams — see our PFC steel guide.

Section Depth h (mm) Width b (mm) Web s (mm) Flange t (mm) Mass (kg/m) Area (cm²) I y-y (cm⁴) Wel y-y (cm³)
100 x 50 x 10 PFC 100 50 5 8.5 10.2 13 208 41.5
125 x 65 x 15 PFC 125 65 5.5 9.5 14.8 18.8 483 77.3
150 x 75 x 18 PFC 150 75 5.5 10 17.9 22.8 861 115
150 x 90 x 24 PFC 150 90 6.5 12 23.9 30.4 1,160 155
180 x 75 x 20 PFC 180 75 6 10.5 20.3 25.9 1,370 152
180 x 90 x 26 PFC 180 90 6.5 12.5 26.1 33.2 1,820 202
200 x 75 x 23 PFC 200 75 6 12.5 23.4 29.9 1,960 196
200 x 90 x 30 PFC 200 90 7 14 29.7 37.9 2,520 252
230 x 75 x 26 PFC 230 75 6.5 12.5 25.7 32.7 2,750 239
230 x 90 x 32 PFC 230 90 7.5 14 32.2 41 3,520 306
260 x 75 x 28 PFC 260 75 7 12 27.6 35.1 3,620 278
260 x 90 x 35 PFC 260 90 8 14 34.8 44.4 4,730 364
300 x 90 x 41 PFC 300 90 9 15.5 41.4 52.7 7,220 481
300 x 100 x 46 PFC 300 100 9 16.5 45.5 58 8,230 549
380 x 100 x 54 PFC 380 100 9.5 17.5 54 68.7 15,000 791
430 x 100 x 64 PFC 430 100 11 19 64.4 82.1 21,900 1,020

What About RSJs?

“RSJ” (Rolled Steel Joist) remains the most common term in the building trade, but modern structural engineers typically specify Universal Beams (UB) or Universal Columns (UC) by their exact designation. The original tapered-flange RSJ has largely been replaced by the parallel-flange UB shown above, so for sizing and weights use the UB table. See also RSJ cost.

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Buy Steel Beams Cut to Size

UB, UC and PFC in S355 grade, cut to your length and delivered across mainland UK. 5–10 working day lead time, offload assistance available — see delivery & lead times.

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Frequently Asked Questions

What does the beam size 203 x 133 x 25 mean?

Nominal depth (203mm), nominal flange width (133mm) and mass per metre (25kg/m). Always quote all three when ordering.

What is the second moment of area (I) of a steel beam?

I (also called the moment of inertia) measures a section’s stiffness in bending about an axis — a higher I means less deflection under load. The values in this chart are about the major (y-y) axis, in cm⁴.

What is the elastic section modulus (Wel)?

Wel relates a section’s bending resistance to stress; engineers use it with the steel grade to check bending capacity. Values here are major-axis, in cm³.

Is an RSJ the same as a universal beam?

In everyday UK use, yes — “RSJ” is trade shorthand for a steel beam, and the modern equivalent is the parallel-flange Universal Beam (UB) in the chart above.

What is the difference between a UB and a UC?

A UB is deeper than it is wide and spans horizontal openings; a UC is roughly square and carries vertical loads as a post or column.

What steel grade are UK beams?

Standard UK structural beams are commonly S355 to BS EN 10025-2, with a minimum yield strength of 355 N/mm².

How do I work out the total weight of my beam?

Multiply the mass per metre by the length in metres. For a quick figure across sections, use our beam weight calculator.

Can I get steel beams cut to size?

Yes — Rackerman supplies UB, UC and PFC cut to your required length in S355 grade, delivered across mainland UK.