LB 225 (ISLB 225)

I-beam — 23.47 kg per metre, 29.9 cm² cross-sectional area. IS 808 Table 2 - Light/Junior Beams.

zyB 100D 225T 8.6R2 6R1 12t 5.8
Mass per metre
23.47kg/m
Sectional area
29.9cm²
Depth
225mm
Width
100mm

Light & Junior Beams (LB, JB). Reproduced as printed in IS 808 Table 2 - Light/Junior Beams.

LB 225 section properties

As printed in IS 808 Table 2 - Light/Junior Beams. 225 mm deep, 100 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 225 mm
Width of flange B 100 mm
Thickness of web t 5.8 mm
Thickness of flange T 8.6 mm
Flange slope 98 °
Root radius R1 12 mm
Toe radius R2 6 mm

Mass and area

Mass per metre M 23.47 kg/m
Sectional area A 29.9 cm²

Major axis (z-z)

Second moment of area Izz 2,500 cm⁴
Radius of gyration rzz 91.4 mm
Elastic section modulus Zzz 222 cm³
Plastic section modulus Zpz 254 cm³

Minor axis (y-y)

Second moment of area Iyy 112 cm⁴
Radius of gyration ryy 19.4 mm
Elastic section modulus Zyy 22.5 cm³
Plastic section modulus Zpy 39.2 cm³

Torsion and warping

Torsion constant (St Venant) It 8.47 cm⁴
Warping constant Iw 16,700 cm⁶

What a length of LB 225 weighs

Total weight is the mass per metre multiplied by the length and the number of pieces. Ten pieces of LB 225 at six metres each is 23.47 × 6 × 10 = 1,408 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: 29.9 cm² of steel at 7 850 kg/m³ is 23.47 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 LB 225

What is the weight of LB 225 per metre?

IS 808 : 2021 gives LB 225 a mass of 23.47 kg per metre. Its printed cross-sectional area of 29.9 cm² agrees: 29.9 cm² of steel at 7 850 kg/m³ works out at 23.47 kg per metre.

How much does a 6 m length of LB 225 weigh?

140.82 kg. Mass per metre times length: 23.47 × 6. Ten such pieces come to 1408 kg.

Is LB 225 the same as ISLB 225?

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 ISLB 225 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 LB 225?

225 mm deep and 100 mm wide, with a 5.8 mm web and 8.6 mm flanges.

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Where these figures come from. IS 808 Table 2 - Light/Junior 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.