ISMB 400 weight and dimensions
61.55 kg/m · 41.36 lb/ft
ISMB 400 is a 400 mm deep beam with a 140 mm flange, 8.9 mm web and 16 mm flange thickness. It weighs 61.55 kg per metre (41.36 lb/ft). It belongs to the ISMB medium weight beam series, Indian Standard (IS 808).
ISMB 400 weight calculator
Weight of standard lengths
| Pieces | 6 m each (kg) | 12 m each (kg) |
|---|---|---|
| 1 | 369.3 | 738.6 |
| 5 | 1,846.5 | 3,693.0 |
| 10 | 3,693.0 | 7,386.0 |
| 20 | 7,386.0 | 14,772.0 |
| 50 | 18,465.0 | 36,930.0 |
Pieces per tonne
| 6 m lengths per metric tonne | 2.7 |
| 12 m lengths per metric tonne | 1.4 |
| Length per tonne | 16.2 m |
Useful for converting a tonnage order into a number of bars.
Surface area for painting
| Per metre of length | 1.318 m²/m |
| Per foot of length | 4.32 ft²/ft |
| Per tonne of steel | 21.4 m²/t |
| A 12 m length | 15.82 m² |
Outside perimeter × length, all faces, calculated from the dimensions. Use it to estimate paint, primer, fireproofing or galvanizing quantities.
Cross-section
Drawn to scale. Dimensions in mm.
Dimensions
| Depth h | 400 mm | 15.748 in |
| Flange width b | 140 mm | 5.512 in |
| Web thickness tw | 8.9 mm | 0.350 in |
| Flange thickness tf | 16 mm | 0.630 in |
| Root radius r | 14 mm | 0.551 in |
| Toe radius r2 | 7 mm | 0.276 in |
| Flange slope (deg) | 98° | |
| Mass | 61.55 kg/m | 41.36 lb/ft |
Section properties
| Property | Value | Unit |
|---|---|---|
| Area | 78.40 | cm² |
| Moment of inertia Ix | 20,400 | cm⁴ |
| Moment of inertia Iy | 622 | cm⁴ |
| Elastic modulus Zx | 1,020 | cm³ |
| Elastic modulus Zy | 88.80 | cm³ |
| Plastic modulus Zpx | 1,170 | cm³ |
| Plastic modulus Zpy | 149 | cm³ |
| Radius of gyration rx | 16.10 | cm |
| Radius of gyration ry | 2.81 | cm |
| Torsion constant J | 59.60 | cm⁴ |
Equivalent sections in other standards
The closest sections by depth and weight. They are not direct substitutes: check bending, buckling and connection details before swapping one for another.
ISMB 400 and its closest equivalents, drawn over each other at the same scale.
| Section | Standard | Depth (mm) | kg/m | Weight vs ISMB 400 |
|---|---|---|---|---|
| ISMB 400 | IS | 400 | 61.55 | — |
| IPE 400 | EN | 400 | 66.30 | +7.7% |
| IPE 360 | EN | 360 | 57.09 | -7.2% |
| W16x40 | AISC | 406 | 60.00 | -2.5% |
| W16x45 | AISC | 409 | 67.00 | +8.9% |
ISMB series weights
Next lighter: ISMB 350 (52.33 kg/m). Next heavier: ISMB 450 (72.38 kg/m).
Stiffness and strength per kilogram
The elastic section modulus Zx governs bending strength. Dividing it by the weight shows how efficiently each size uses its steel: higher is better when weight is the cost driver.
| Section | kg/m | Ix (cm⁴) | Zx (cm³) | Zx per kg/m |
|---|---|---|---|---|
| ISMB 250 | 37.30 | 5,130 | 410.0 | 10.99 |
| ISMB 300 | 46.02 | 8,990 | 599.0 | 13.02 |
| ISMB 350 | 52.33 | 13,600 | 779.0 | 14.89 |
| ISMB 400 | 61.55 | 20,400 | 1,020.0 | 16.57 |
| ISMB 450 | 72.38 | 30,400 | 1,350.0 | 18.65 |
| ISMB 500 | 86.88 | 45,200 | 1,800.0 | 20.72 |
| ISMB 550 | 103.64 | 64,900 | 2,360.0 | 22.77 |
Full table: ISMB weight chart (PDF).
How the weight is calculated
Mass per metre = cross-sectional area × density of steel = 78.40 cm² × 0.785 kg/(cm²·m) = 61.54 kg/m.
Rolled sections are made to a nominal mass, and the actual mass can differ by a few percent within the tolerances of IS 1852. For purchasing, invoicing by weight or checking deliveries, use the producer's stated mass.
Typical uses
Beams of this shape are used as floor and roof beams, lintels, crane girders and frame members, where bending about the strong axis governs.
Frequently asked questions
What is the weight of ISMB 400 per metre?
ISMB 400 weighs 61.55 kg/m, which is 41.36 lb/ft.
How much does a 6 m or 12 m length of ISMB 400 weigh?
A 6 m length weighs about 369.3 kg and a 12 m length about 738.6 kg.
What is the equivalent of ISMB 400 in other standards?
By depth and weight the closest match is IPE 400 (66.3 kg/m, 400 mm deep). Check section properties before substituting one for the other.
Source: IS 808:2021; earlier values from IS 808:1989 and SP 6(1):1964. Values are nominal; verify with the producer before ordering.