Indian Standard Medium Weight Beam per IS 808 : 1989 — depth 125mm, flange width 75mm, web thickness 4.4mm, flange thickness 7.6mm, weight 13.0 kg/m.
| Property | About X-X Axis | About Y-Y Axis |
|---|---|---|
| Moment of Inertia (I) | 4,490,000 mm⁴ (449.0 cm⁴) | 437,000 mm⁴ (43.7 cm⁴) |
| Elastic Section Modulus (Z) | 71,800 mm³ (71.8 cm³) | 11,700 mm³ (11.7 cm³) |
| Plastic Section Modulus (Zp) | 83,200 mm³ (83.2 cm³) | 18,700 mm³ (18.7 cm³) |
| Radius of Gyration (r) | 52.0 mm | 16.2 mm |
| Distance to Extreme Fibre (c) | 62.5 mm (d/2) | 37.5 mm (b/2) |
| Shape Factor (Zp/Z) | 1.159 | 1.598 |
| Torsional Constant (It) | 42,300 mm⁴ (4.2 cm⁴) | |
| Warping Constant (Iw) | 2,370,000,000 mm⁶ | |
| Polar Moment (Ip = Ix + Iy) | 4,927,000 mm⁴ (492.7 cm⁴) | |
Useful for paint estimation, fire protection coating quantities, and section analysis:
Surface area calculated from full cross-section perimeter including flange tips. Shear area Av = d × tw per IS 800 : 2007 cl. 8.4. Surface/mass ratio used for estimating paint and fireproofing coverage per kg of steel.
Calculated per IS 800 : 2007 (limit state design) using partial safety factor γm0 = 1.10. Values assume the section is fully laterally restrained. Reduce for unsupported lengths per IS 800 cl. 8.2.
| Grade | Plastic Moment Mp (X-X) | Plastic Moment Mp (Y-Y) | Axial Capacity (Short) |
|---|---|---|---|
| E 250 | 18.9 kN·m | 4.2 kN·m | 377 kN |
| E 350 | 26.5 kN·m | 5.9 kN·m | 528 kN |
| E 410 | 31.0 kN·m | 7.0 kN·m | 619 kN |
| E 450 | 34.0 kN·m | 7.6 kN·m | 679 kN |
Mp = Zp × fy / γm0. Axial capacity = A × fy / γm0 for short, fully-restrained columns. For longer columns, apply slenderness reduction per IS 800 cl. 7.1.2.
| Standard | Equivalent Section | Depth | Weight |
|---|---|---|---|
| India (IS 808) | ISMB 125 | 125 mm | 13.0 kg/m |
| Europe (EN) | IPE 120 | — | — |
| UK (BS) | 127×76×13 UB | — | — |
| USA (ASTM) | W5×16 | — | — |
| Japan (JIS) | H 125×125 | — | — |
| Germany (DIN) | I 120 | — | — |
Equivalence based on closest matching depth and weight. Note that ISMB has tapered flanges (8° slope per IS 808) while IPE, UB, and W-shapes have parallel flanges. Always verify exact properties from the actual standard before substituting in design calculations.
| Grade | Yield (MPa) | UTS (MPa) | Elong. | Application |
|---|---|---|---|---|
| E250 (Fe 410W) | 250 | 410 | 23% | General construction |
| E275 (Fe 440) | 275 | 440 | 22% | Commercial buildings |
| E300 | 300 | 440 | 22% | Industrial structures |
| E350 (Fe 490) | 350 | 490 | 22% | Heavy industrial, bridges |
| E410 (Fe 540) | 410 | 540 | 20% | Heavy structural, offshore |
| E450 (Fe 570) | 450 | 570 | 20% | Bridges, towers |