MB 250 (ISMB 250)

I-beam — 37.3 kg per metre, 47.5 cm² cross-sectional area. IS 808 Table 1 - Medium & Wide Flange Beams.

zyB 125D 250T 12.5R2 6.5R1 13t 6.9
Mass per metre
37.3kg/m
Sectional area
47.5cm²
Depth
250mm
Width
125mm

Medium & Wide Flange Beams (MB, WB). Reproduced as printed in IS 808 Table 1 - Medium & Wide Flange Beams.

MB 250 section properties

As printed in IS 808 Table 1 - Medium & Wide Flange Beams. 250 mm deep, 125 mm wide. Units are shown on every row, because the two standards on this site use different ones for the radius of gyration.

Dimensions

Depth of section D 250 mm
Width of flange B 125 mm
Thickness of web t 6.9 mm
Thickness of flange T 12.5 mm
Flange slope 98 °
Root radius R1 13 mm
Toe radius R2 6.5 mm

Mass and area

Mass per metre M 37.3 kg/m
Sectional area A 47.5 cm²

Major axis (z-z)

Second moment of area Izz 5,130 cm⁴
Radius of gyration rzz 103 mm
Elastic section modulus Zzz 410 cm³
Plastic section modulus Zpz 465 cm³

Minor axis (y-y)

Second moment of area Iyy 334 cm⁴
Radius of gyration ryy 26.5 mm
Elastic section modulus Zyy 53.5 cm³
Plastic section modulus Zpy 89.7 cm³

Torsion and warping

Torsion constant (St Venant) It 25.5 cm⁴
Warping constant Iw 57,300 cm⁶

What a length of MB 250 weighs

Total weight is the mass per metre multiplied by the length and the number of pieces. Ten pieces of MB 250 at six metres each is 37.3 × 6 × 10 = 2,238 kg. There is nothing else to it — the standard publishes the mass, so no one needs to compute it from the area.

You can check that mass against the area on this page: 47.5 cm² of steel at 7 850 kg/m³ is 37.29 kg/m. Every row in this dataset was checked that way, which is how the contradictions flagged on some of these pages were found.

Work it out for your own lengths and quantities →

Common questions about MB 250

What is the weight of MB 250 per metre?

IS 808 : 2021 gives MB 250 a mass of 37.3 kg per metre. Its printed cross-sectional area of 47.5 cm² agrees: 47.5 cm² of steel at 7 850 kg/m³ works out at 37.29 kg per metre.

How much does a 6 m length of MB 250 weigh?

223.80 kg. Mass per metre times length: 37.3 × 6. Ten such pieces come to 2238 kg.

Is MB 250 the same as ISMB 250?

It is the same section under the name IS 808 : 2021 gives it — the 2021 revision of IS 808 dropped the "IS" prefix, so a drawing saying ISMB 250 means this section. Check the edition before assuming the figures match, though: this page publishes the current tables, and a great many tables in circulation were copied from the 1989 edition.

What are the dimensions of MB 250?

250 mm deep and 125 mm wide, with a 6.9 mm web and 12.5 mm flanges.

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Where these figures come from. IS 808 Table 1 - Medium & Wide Flange Beams Section properties are facts published in the standards, and they are reproduced here as printed. Where a standard contradicts itself, both of its figures are shown and neither is corrected.

What is ours. The selection and arrangement of these tables, the checks run against them, and the findings those checks produced — which rows disagree with themselves, which figures were superseded by amendment, and which could not be read — are QuickBOQ’s work, and so is this wording. Quote the numbers freely; they belong to everyone. Copying the compilation and the commentary is a different thing, and we would rather you linked to it.