NPB 550 × 210

I-beam — 122.52 kg per metre, 156 cm² cross-sectional area. IS 808 Table 3 - Narrow Parallel Flange Beams.

zyB 212D 556T 20.2R1 24t 12.7
Mass per metre
122.52kg/m
Sectional area
156cm²
Depth
556mm
Width
212mm

Narrow Parallel Flange Beams (NPB). Reproduced as printed in IS 808 Table 3 - Narrow Parallel Flange Beams.

NPB 550 × 210 section properties

As printed in IS 808 Table 3 - Narrow Parallel Flange Beams. 556 mm deep, 212 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 556 mm
Width of flange B 212 mm
Thickness of web t 12.7 mm
Thickness of flange T 20.2 mm
Flange slope 90 °
Root radius R1 24 mm
Toe radius R2 0 mm

Mass and area

Mass per metre M 122.52 kg/m
Sectional area A 156 cm²

Major axis (z-z)

Second moment of area Izz 79,100 cm⁴
Radius of gyration rzz 225 mm
Elastic section modulus Zzz 2,840 cm³
Plastic section modulus Zpz 3,260 cm³

Minor axis (y-y)

Second moment of area Iyy 3,220 cm⁴
Radius of gyration ryy 45.4 mm
Elastic section modulus Zyy 304 cm³
Plastic section modulus Zpy 480 cm³

Torsion and warping

Torsion constant (St Venant) It 187 cm⁴
Warping constant Iw 23,00,000 cm⁶

What a length of NPB 550 × 210 weighs

Total weight is the mass per metre multiplied by the length and the number of pieces. Ten pieces of NPB 550 × 210 at six metres each is 122.52 × 6 × 10 = 7,351 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: 156 cm² of steel at 7 850 kg/m³ is 122.46 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 NPB 550 × 210

What is the weight of NPB 550 × 210 per metre?

IS 808 : 2021 gives NPB 550 × 210 a mass of 122.52 kg per metre. Its printed cross-sectional area of 156 cm² agrees: 156 cm² of steel at 7 850 kg/m³ works out at 122.46 kg per metre.

How much does a 6 m length of NPB 550 × 210 weigh?

735.12 kg. Mass per metre times length: 122.52 × 6. Ten such pieces come to 7351 kg.

What are the dimensions of NPB 550 × 210?

556 mm deep and 212 mm wide, with a 12.7 mm web and 20.2 mm flanges.

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Where these figures come from. IS 808 Table 3 - Narrow 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.