∠ 100 × 100 × 12 (ISA 100x100x12)

angle — 17.83 kg per metre, 22.7 cm² cross-sectional area. IS 808 Table 9 - Equal Leg Angles.

xyB 100A 100t 12R1 8.5
Mass per metre
17.83kg/m
Sectional area
22.7cm²
Leg A
100mm
Leg B
100mm
Thickness
12mm

Equal Leg Angles. Reproduced as printed in IS 808 Table 9 - Equal Leg Angles.

A radius of gyration here disagrees with this row’s own I and A

  • rvv is printed 196; √(I/A) from this row gives 19.6 — the printed figure is the value in mm, in a column headed cm.

∠ 100 × 100 × 12 section properties

As printed in IS 808 Table 9 - Equal Leg Angles. legs 100 × 100 mm, 12 mm thick. Units are shown on every row, because the two standards on this site use different ones for the radius of gyration.

Dimensions

Length of leg A A 100 mm
Length of leg B B 100 mm
Thickness of leg t 12 mm
Root radius R1 8.5 mm
Toe radius R2 0 mm

Mass and area

Mass per metre M 17.83 kg/m
Sectional area A 22.7 cm²

Centroid

Centroid from the back of leg A Cx 29.3 mm
Centroid from the back of leg B Cy 29.3 mm

About x-x

Second moment of area Ixx 210 cm⁴
Radius of gyration rxx 30.4 mm
Elastic section modulus Zxx 29.8 cm³
Plastic section modulus Zpx 53.6 cm³

About y-y

Second moment of area Iyy 210 cm⁴
Radius of gyration ryy 30.4 mm
Elastic section modulus Zyy 29.8 cm³
Plastic section modulus Zpy 53.7 cm³

Principal axes (u-u, v-v)

Second moment of area Iuu 333 cm⁴
Second moment of area Ivv 87.2 cm⁴
Radius of gyration ruu 38.3 mm
Radius of gyration rvv 196 mm
Tangent of the principal axis angle tan α 0.79

Torsion and warping

Torsion constant (St Venant) It 10.8 cm⁴

What a length of ∠ 100 × 100 × 12 weighs

Total weight is the mass per metre multiplied by the length and the number of pieces. Ten pieces of ∠ 100 × 100 × 12 at six metres each is 17.83 × 6 × 10 = 1,070 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: 22.7 cm² of steel at 7 850 kg/m³ is 17.82 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 ∠ 100 × 100 × 12

What is the weight of ∠ 100 × 100 × 12 per metre?

IS 808 : 2021 gives ∠ 100 × 100 × 12 a mass of 17.83 kg per metre. Its printed cross-sectional area of 22.7 cm² agrees: 22.7 cm² of steel at 7 850 kg/m³ works out at 17.82 kg per metre.

How much does a 6 m length of ∠ 100 × 100 × 12 weigh?

106.98 kg. Mass per metre times length: 17.83 × 6. Ten such pieces come to 1070 kg.

Is ∠ 100 × 100 × 12 the same as ISA 100x100x12?

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 ISA 100x100x12 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.

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Where these figures come from. IS 808 Table 9 - Equal Leg Angles 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.