Complete RSJ Size Chart 2026: Dimensions, Weights, and Safe Loads for All Common Sections
This comprehensive reference chart provides dimensions, weights, and safe working loads for all commonly available RSJ (Rolled Steel Joist) and Universal Beam sections in the UK market for 2026. Use this as your quick-reference guide for beam selection and specification.
How to Read RSJ Designations
RSJ beams are typically designated as: Depth × Width × Weight
Example: 203 × 133 × 25
- 203mm: Overall depth (height) of the beam
- 133mm: Flange width
- 25 kg/m: Mass per meter
Complete RSJ/UB Size Chart
Small Sections (120-178mm depth)
| Designation | Depth (mm) | Width (mm) | Web (mm) | Flange (mm) | Weight (kg/m) | I_x (cm⁴) | Z_x (cm³) |
|---|---|---|---|---|---|---|---|
| 127×76×13 | 127 | 76 | 4.0 | 7.6 | 13.0 | 473 | 83 |
| 152×89×16 | 152 | 89 | 4.5 | 7.7 | 16.0 | 869 | 119 |
| 152×127×37 | 152 | 127 | 6.4 | 10.7 | 37.0 | 1,358 | 159 |
| 178×102×19 | 178 | 102 | 4.8 | 7.9 | 19.0 | 1,357 | 146 |
| 178×127×26 | 178 | 127 | 5.8 | 10.2 | 26.0 | 1,690 | 194 |
** Safe Working Load Examples (simply supported, span dependent):**
- 152×127×37 at 2.5m: ~10 kN/m
- 178×102×19 at 3.0m: ~5 kN/m
Medium Sections (203mm depth)
| Designation | Depth (mm) | Width (mm) | Web (mm) | Flange (mm) | Weight (kg/m) | I_x (cm⁴) | Z_x (cm³) |
|---|---|---|---|---|---|---|---|
| 203×102×23 | 203 | 102 | 5.4 | 9.3 | 23.0 | 2,107 | 197 |
| 203×133×25 | 203 | 133 | 5.7 | 7.8 | 25.0 | 2,896 | 208 |
| 203×133×30 | 203 | 133 | 6.4 | 9.6 | 30.0 | 3,438 | 245 |
| 203×203×46 | 203 | 203 | 7.2 | 11.0 | 46.0 | 4,568 | 410 |
| 203×203×52 | 203 | 203 | 7.9 | 12.5 | 52.0 | 5,261 | 472 |
Safe Working Load Examples:
- 203×133×25 at 3.5m: ~6.5 kN/m
- 203×133×30 at 4.0m: ~6.0 kN/m
- 203×203×52 at 4.0m: ~12 kN/m
Large Sections (254mm depth)
| Designation | Depth (mm) | Width (mm) | Web (mm) | Flange (mm) | Weight (kg/m) | I_x (cm⁴) | Z_x (cm³) |
|---|---|---|---|---|---|---|---|
| 254×102×22 | 254 | 102 | 5.7 | 6.8 | 22.0 | 2,842 | 215 |
| 254×102×25 | 254 | 102 | 6.0 | 8.4 | 25.0 | 3,292 | 248 |
| 254×102×28 | 254 | 102 | 6.3 | 10.0 | 28.0 | 3,716 | 279 |
| 254×146×31 | 254 | 146 | 6.0 | 8.6 | 31.0 | 6,572 | 354 |
| 254×146×37 | 254 | 146 | 6.3 | 10.9 | 37.0 | 7,628 | 411 |
| 254×146×43 | 254 | 146 | 7.2 | 12.7 | 43.0 | 8,503 | 464 |
| 254×254×73 | 254 | 254 | 8.6 | 14.2 | 73.0 | 11,313 | 777 |
| 254×254×89 | 254 | 254 | 10.3 | 17.3 | 89.0 | 13,640 | 950 |
Safe Working Load Examples:
- 254×146×31 at 5.0m: ~5.5 kN/m
- 254×146×37 at 5.5m: ~5.4 kN/m
- 254×254×89 at 5.0m: ~20 kN/m
Extra Large Sections (305mm+ depth)
| Designation | Depth (mm) | Width (mm) | Web (mm) | Flange (mm) | Weight (kg/m) | I_x (cm⁴) | Z_x (cm³) |
|---|---|---|---|---|---|---|---|
| 305×102×25 | 305 | 102 | 5.8 | 6.8 | 25.0 | 4,392 | 265 |
| 305×102×28 | 305 | 102 | 6.0 | 8.8 | 28.0 | 5,180 | 311 |
| 305×102×33 | 305 | 102 | 6.6 | 10.8 | 33.0 | 6,070 | 364 |
| 305×165×40 | 305 | 165 | 6.0 | 10.2 | 40.0 | 12,350 | 568 |
| 305×165×46 | 305 | 165 | 6.7 | 11.8 | 46.0 | 14,100 | 652 |
| 305×165×54 | 305 | 165 | 7.9 | 13.7 | 54.0 | 16,100 | 749 |
| 305×305×97 | 305 | 305 | 9.9 | 15.4 | 97.0 | 26,390 | 1,472 |
| 305×305×118 | 305 | 305 | 12.0 | 18.7 | 118.0 | 31,930 | 1,784 |
Safe Working Load Examples:
- 305×165×40 at 6.0m: ~6.3 kN/m
- 305×165×54 at 7.0m: ~5.5 kN/m
- 305×305×118 at 7.0m: ~17 kN/m
Very Large Sections (356-457mm depth)
| Designation | Depth (mm) | Width (mm) | Web (mm) | Flange (mm) | Weight (kg/m) | I_x (cm⁴) | Z_x (cm³) |
|---|---|---|---|---|---|---|---|
| 356×171×45 | 356 | 171 | 6.9 | 9.7 | 45.0 | 17,100 | 764 |
| 356×171×51 | 356 | 171 | 7.4 | 11.5 | 51.0 | 19,610 | 876 |
| 356×171×57 | 356 | 171 | 8.1 | 13.0 | 57.0 | 21,880 | 979 |
| 356×171×67 | 356 | 171 | 9.1 | 15.7 | 67.0 | 25,400 | 1,142 |
| 406×178×54 | 406 | 178 | 7.7 | 10.9 | 54.0 | 24,380 | 987 |
| 406×178×60 | 406 | 178 | 7.9 | 12.8 | 60.0 | 27,690 | 1,122 |
| 406×178×67 | 406 | 178 | 8.8 | 14.3 | 67.0 | 30,580 | 1,244 |
| 406×178×74 | 406 | 178 | 9.5 | 16.0 | 74.0 | 33,570 | 1,367 |
| 457×191×67 | 457 | 191 | 8.5 | 12.7 | 67.0 | 35,110 | 1,266 |
| 457×191×74 | 457 | 191 | 9.0 | 14.5 | 74.0 | 39,360 | 1,424 |
| 457×191×82 | 457 | 191 | 9.9 | 16.0 | 82.0 | 43,270 | 1,570 |
| 457×191×89 | 457 | 191 | 10.5 | 17.7 | 89.0 | 47,170 | 1,715 |
Note: These heavy sections are primarily for commercial/industrial applications. Residential use is rare.
Using This Chart
Quick Beam Selection Process
Step 1: Determine Required Section Modulus (Z)
From preliminary calculations: Z_required = M / σ_allowable
Where:
- M = Maximum bending moment (kNm)
- σ_allowable = 165 N/mm² (with safety factors for S275 steel)
Step 2: Find Beam with Adequate Z
Scan the Z_x column to find sections with Z ≥ Z_required
Example: Need Z = 350 cm³
- 203×203×52: Z = 472 cm³ ✓
- 254×146×31: Z = 354 cm³ ✓
- 254×146×37: Z = 411 cm³ ✓
Step 3: Check Deflection
Using I value, calculate deflection: δ = (5 × w × L⁴) / (384 × E × I)
Verify δ < span/360 for floors or span/200 for roofs
Step 4: Select Most Economical
Usually the lightest (cheapest) beam that passes both strength and deflection checks.
European IPE Sections (Common in Poland/EU)
Comparison to UK RSJ:
| IPE Size | Approx. UK Equivalent | Depth (mm) | Width (mm) | Weight (kg/m) | I_x (cm⁴) |
|---|---|---|---|---|---|
| IPE 140 | 152×127×37 | 140 | 73 | 12.9 | 541 |
| IPE 160 | 152×89×16 | 160 | 82 | 15.8 | 869 |
| IPE 180 | 178×102×19 | 180 | 91 | 18.8 | 1,317 |
| IPE 200 | 203×133×25 | 200 | 100 | 22.4 | 1,943 |
| IPE 220 | 203×133×30 | 220 | 110 | 26.2 | 2,772 |
| IPE 240 | 254×102×22 | 240 | 120 | 30.7 | 3,892 |
| IPE 270 | 254×146×31 | 270 | 135 | 36.1 | 5,790 |
| IPE 300 | 305×165×40 | 300 | 150 | 42.2 | 8,356 |
| IPE 330 | 305×165×46 | 330 | 160 | 49.1 | 11,770 |
| IPE 360 | 356×171×51 | 360 | 170 | 57.1 | 16,270 |
Note: IPE sections are not direct equivalents – always verify properties before substituting.
Weight Chart for Quick Reference
Approximate weights for common lengths:
| Beam Size | 3m Length | 4m Length | 5m Length | 6m Length |
|---|---|---|---|---|
| 152×127×37 | 111 kg | 148 kg | 185 kg | 222 kg |
| 203×133×25 | 75 kg | 100 kg | 125 kg | 150 kg |
| 203×133×30 | 90 kg | 120 kg | 150 kg | 180 kg |
| 254×146×31 | 93 kg | 124 kg | 155 kg | 186 kg |
| 254×146×37 | 111 kg | 148 kg | 185 kg | 222 kg |
| 305×165×40 | 120 kg | 160 kg | 200 kg | 240 kg |
Handling considerations:
- <100kg: 2-3 people can lift safely
- 100-150kg: 3-4 people or mechanical assistance
-
150kg: Crane, hoist, or engine lift required
Material Grades
Most UK RSJ beams are supplied in:
S275:
- Yield strength: 275 N/mm²
- Most common grade
- Suitable for most residential/light commercial
S355:
- Yield strength: 355 N/mm²
- ~29% stronger than S275
- Used for heavier loads or longer spans
S450/S460:
- Yield strength: 450-460 N/mm²
- High-performance applications only- Less common, higher cost
Always verify grade with supplier and ensure it matches engineering specifications.
Conclusion
This comprehensive size chart provides quick reference data for RSJ and Universal Beam selection. Use the section modulus (Z) and second moment of area (I) values for preliminary beam sizing, then always verify final selection with a chartered structural engineer’s calculations.
Remember:
- Dimensions are nominal (manufacturing tolerances apply)
- I and Z values critical for deflection and strength calculations
- Always purchase beams to exact engineer specification
- Verify steel grade matches design requirements
For detailed calculations and specific application advice, use our online calculators and consult with a structural engineer.
Disclaimer: Tables provided for reference only. All beam selections must be verified by a chartered structural engineer before specification and purchase.
