MB 350 (ISMB 350)

I-beam — 52.33 kg per metre, 66.7 cm² cross-sectional area. IS 808 Table 1 - Medium & Wide Flange Beams.

zyB 140D 350T 14.2R2 7R1 14t 8.1
Mass per metre
52.33kg/m
Sectional area
66.7cm²
Depth
350mm
Width
140mm

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

MB 350 section properties

As printed in IS 808 Table 1 - Medium & Wide Flange Beams. 350 mm deep, 140 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 350 mm
Width of flange B 140 mm
Thickness of web t 8.1 mm
Thickness of flange T 14.2 mm
Flange slope 98 °
Root radius R1 14 mm
Toe radius R2 7 mm

Mass and area

Mass per metre M 52.33 kg/m
Sectional area A 66.7 cm²

Major axis (z-z)

Second moment of area Izz 13,600 cm⁴
Radius of gyration rzz 142 mm
Elastic section modulus Zzz 779 cm³
Plastic section modulus Zpz 889 cm³

Minor axis (y-y)

Second moment of area Iyy 537 cm⁴
Radius of gyration ryy 28.3 mm
Elastic section modulus Zyy 76.8 cm³
Plastic section modulus Zpy 129 cm³

Torsion and warping

Torsion constant (St Venant) It 43.1 cm⁴
Warping constant Iw 1,83,000 cm⁶

What a length of MB 350 weighs

Total weight is the mass per metre multiplied by the length and the number of pieces. Ten pieces of MB 350 at six metres each is 52.33 × 6 × 10 = 3,140 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: 66.7 cm² of steel at 7 850 kg/m³ is 52.36 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 350

What is the weight of MB 350 per metre?

IS 808 : 2021 gives MB 350 a mass of 52.33 kg per metre. Its printed cross-sectional area of 66.7 cm² agrees: 66.7 cm² of steel at 7 850 kg/m³ works out at 52.36 kg per metre.

How much does a 6 m length of MB 350 weigh?

313.98 kg. Mass per metre times length: 52.33 × 6. Ten such pieces come to 3140 kg.

Is MB 350 the same as ISMB 350?

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 350 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 350?

350 mm deep and 140 mm wide, with a 8.1 mm web and 14.2 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.