IS 808 Angle Weight Chart — ISA Equal and Unequal Section Sizes

The IS 808 angle weight chart gives the mass per metre for every standard ISA section specified in IS:808-1989. For equal-leg angles, the values range from 0.9 kg/m (ISA 20×20×3) to 73.6 kg/m (ISA 200×200×25). For unequal-leg angles, the range runs from 1.1 kg/m (ISA 30×20×3) to 47.1 kg/m (ISA 200×150×18). Use these values directly for material take-off, freight estimation, and fabrication planning.

What IS:808-1989 Covers for Angle Sections

IS:808-1989, titled Dimensions for Hot Rolled Steel Beam, Column, Channel and Angle Sections, is the primary Indian Standard for structural steel sections. It was reaffirmed in 2001 and remains the legislative reference for all section procurement in India, covering both angles and beams like the ISMB 250, ISMB 300, and ISMB 350. The standard defines the leg dimensions, thickness, root radius, toe radius, cross-sectional area, and mass per metre for every ISA designation. Equal-leg angles carry the designation ISA A×A×t (e.g. ISA 75×75×8) while unequal-leg angles are designated ISA A×B×t (e.g. ISA 100×75×8).

Fabricators in India often refer to angle sections as "angle iron" — the term MS angle ka weight refers to the mass per metre of mild-steel angle sections produced to IS:808. The data in the tables below come directly from IS:808-1989 and match published values from the Jindal Star structural section catalogue.

MS Angle Weight Formula

Formula (equal-leg angle): Weight (kg/m) = (2A − t) × t × 0.7874 / 100

A

Leg length, in millimetres (both legs equal for ISA sections)

t

Leg thickness, in millimetres

0.7874

Constant derived from steel density (7850 kg/m³) × π / 4 / 1000, simplified for the angle section geometry

kg/m

Mass per metre of section length; multiply by length in metres to get total piece weight

This formula is an approximation. The exact values in IS:808-1989 account for the root radius and toe radius of the rolled section, which slightly reduce the theoretical cross-sectional area. For procurement and estimation, always use the tabulated IS:808 values below rather than the formula, since those are the values that mills and suppliers measure against at weighbridge.

IS 808 Equal-Leg Angle Weight Chart (ISA)

Section properties and mass per metre as per IS:808-1989 (Reaffirmed 2001). Mass tolerance: ±2.5% per piece as per IS:1852 — Rolling and Cutting Tolerances for Hot Rolled Steel Products.

IS 808 Unequal-Leg Angle Weight Chart (ISA Unequal)

Section properties as per IS:808-1989 (Reaffirmed 2001). Mass tolerance: ±2.5% per piece as per IS:1852. For unequal-leg angles, the longer leg dimension is stated first in the designation.

Difference Between ISA Equal and ISA Unequal Sections

An ISA equal-leg angle has both legs at the same length — ISA 75×75×8 means both legs are 75 mm long with an 8 mm thickness. An ISA unequal-leg angle has one leg longer than the other — ISA 100×75×8 means the long leg is 100 mm and the short leg is 75 mm. Both types are specified in IS:808-1989 and are rolled in mild steel to IS:2062 E250 or E350 grade by suppliers such as Jindal Star (JSPL).

In structural fabrication, equal-leg angles are used for back-to-back compound sections, lacing bars, purlin cleats, and bracing. Unequal-leg angles are specified when the projection of one leg needs to be longer than the other — common in crane girder flanges and beam-to-column connections where clearance matters. The weight difference between the two types at similar overall size is significant: ISA 100×100×8 weighs 12.1 kg/m while ISA 100×75×8 weighs 10.5 kg/m, a saving of 13% on the section weight.

Worked Example — ISA 75×75×8 Purlin Cleat Order

A structural steel fabricator in Surat is preparing a material take-off for the purlin cleats on an IS:800 portal frame shed. The specification calls for ISA 75×75×8 angle cleats, each 450 mm long, with 48 pieces required across the frame.

Step 1 — Read the IS:808 weight: From the equal-leg angle table above, ISA 75×75×8 = 8.9 kg/m.

Step 2 — Calculate one piece weight: 8.9 kg/m × 0.450 m = 4.005 kg per cleat.

Step 3 — Calculate total theoretical weight: 48 × 4.005 = 192.2 kg.

Step 4 — Apply IS:1852 upper tolerance for procurement: 192.2 × 1.025 = 197.1 kg. Round up to 200 kg for the purchase order to absorb the maximum allowed mass overrun.

The section weight used in Step 1 is the IS:808 tabulated value — not the formula approximation — because this is the value that mill invoices and weighbridge certificates will be measured against. Ordering to the tolerance-adjusted weight prevents a shortfall when the mill delivers material at the upper end of the IS:1852 tolerance band. Use the MetalWeightPro Metal Weight Calculator to cross-check any non-standard length or size instantly, and see our MS Angle Weight Per Meter guide for formula derivation detail.

ISA vs ISUA — Understanding Angle Section Designations

The designation system sometimes causes confusion on shop drawings. IS:808 uses ISA for all angle sections — both equal and unequal. Some older drawings and supplier catalogues use the designation ISUA (Indian Standard Unequal Angle) to distinguish unequal-leg sections, but IS:808-1989 does not use this term. When you see ISUA on a drawing, treat it as equivalent to an ISA unequal-leg section with the same leg dimensions. If in doubt, always refer to the IS:808 section table by dimension rather than by designation name, as the dimensions are unambiguous.