JB 175 (ISJB 175)

I-beam — 8.07 kg per metre, 10.2 cm² cross-sectional area. IS 808 Table 2 - Light/Junior Beams.

zyB 50D 175T 4.8R2 1.5R1 5t 3.2
Mass per metre
8.07kg/m
Sectional area
10.2cm²
Depth
175mm
Width
50mm

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

JB 175 section properties

As printed in IS 808 Table 2 - Light/Junior Beams. 175 mm deep, 50 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 175 mm
Width of flange B 50 mm
Thickness of web t 3.2 mm
Thickness of flange T 4.8 mm
Flange slope 91.5 °
Root radius R1 5 mm
Toe radius R2 1.5 mm

Mass and area

Mass per metre M 8.07 kg/m
Sectional area A 10.2 cm²

Major axis (z-z)

Second moment of area Izz 480 cm⁴
Radius of gyration rzz 68.3 mm
Elastic section modulus Zzz 54.9 cm³
Plastic section modulus Zpz 64.2 cm³

Minor axis (y-y)

Second moment of area Iyy 9.65 cm⁴
Radius of gyration ryy 9.69 mm
Elastic section modulus Zyy 3.86 cm³
Plastic section modulus Zpy 6.32 cm³

Torsion and warping

Torsion constant (St Venant) It 0.656 cm⁴
Warping constant Iw 724 cm⁶

What a length of JB 175 weighs

Total weight is the mass per metre multiplied by the length and the number of pieces. Ten pieces of JB 175 at six metres each is 8.07 × 6 × 10 = 484 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: 10.2 cm² of steel at 7 850 kg/m³ is 8.01 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 JB 175

What is the weight of JB 175 per metre?

IS 808 : 2021 gives JB 175 a mass of 8.07 kg per metre. Its printed cross-sectional area of 10.2 cm² agrees: 10.2 cm² of steel at 7 850 kg/m³ works out at 8.01 kg per metre.

How much does a 6 m length of JB 175 weigh?

48.42 kg. Mass per metre times length: 8.07 × 6. Ten such pieces come to 484 kg.

Is JB 175 the same as ISJB 175?

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 ISJB 175 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 JB 175?

175 mm deep and 50 mm wide, with a 3.2 mm web and 4.8 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.