WPB 120 × 120

I-beam — 52.13 kg per metre, 66.4 cm² cross-sectional area. IS 808 Table 4 - Wide Parallel Flange Beams.

zyB 126D 140T 21R1 12t 12.5
Mass per metre
52.13kg/m
Sectional area
66.4cm²
Depth
140mm
Width
126mm

Wide Parallel Flange Beams (WPB). Reproduced as printed in IS 808 Table 4 - Wide Parallel Flange Beams.

WPB 120 × 120 section properties

As printed in IS 808 Table 4 - Wide Parallel Flange Beams. 140 mm deep, 126 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 140 mm
Width of flange B 126 mm
Thickness of web t 12.5 mm
Thickness of flange T 21 mm
Flange slope 90 °
Root radius R1 12 mm
Toe radius R2 0 mm

Mass and area

Mass per metre M 52.13 kg/m
Sectional area A 66.4 cm²

Major axis (z-z)

Second moment of area Izz 2,010 cm⁴
Radius of gyration rzz 55.1 mm
Elastic section modulus Zzz 288 cm³
Plastic section modulus Zpz 350 cm³

Minor axis (y-y)

Second moment of area Iyy 702 cm⁴
Radius of gyration ryy 32.5 mm
Elastic section modulus Zyy 111 cm³
Plastic section modulus Zpy 171 cm³

Torsion and warping

Torsion constant (St Venant) It 90.5 cm⁴
Warping constant Iw 24,700 cm⁶

What a length of WPB 120 × 120 weighs

Total weight is the mass per metre multiplied by the length and the number of pieces. Ten pieces of WPB 120 × 120 at six metres each is 52.13 × 6 × 10 = 3,128 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: 66.4 cm² of steel at 7 850 kg/m³ is 52.12 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 WPB 120 × 120

What is the weight of WPB 120 × 120 per metre?

IS 808 : 2021 gives WPB 120 × 120 a mass of 52.13 kg per metre. Its printed cross-sectional area of 66.4 cm² agrees: 66.4 cm² of steel at 7 850 kg/m³ works out at 52.12 kg per metre.

How much does a 6 m length of WPB 120 × 120 weigh?

312.78 kg. Mass per metre times length: 52.13 × 6. Ten such pieces come to 3128 kg.

What are the dimensions of WPB 120 × 120?

140 mm deep and 126 mm wide, with a 12.5 mm web and 21 mm flanges.

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Where these figures come from. IS 808 Table 4 - Wide Parallel 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.