IS 808 is the Bureau of Indian Standards code that defines dimensions, mass per metre, and sectional properties for all hot-rolled structural steel sections used in India — ISMB beams, ISMC channels, ISA angles, ISHB heavy beams, ISWB wide flange, and ISSC columns.
The master standard for all hot-rolled structural steel sections in India
Ensures every Indian steel mill (SAIL, Tata, JSW, JSPL) and every structural engineer uses the same dimensions and theoretical weights for the same section name. Without IS 808, a "200 mm beam" could mean different things from different suppliers.
Beams (ISMB, ISJB, ISLB, ISWB, ISNPB, ISWPB), columns (ISSC, ISHB), channels (ISMC, ISMCP), angles (ISA equal and unequal), and bearing pile sections (ISPBP). All in a single standard reference document.
IS 808 is the reference for all Indian steel supplier invoices and Mill Test Certificates (MTC). Weight is billed on theoretical mass per metre from IS 808 tables — not actual scale weight. Knowing the IS 808 values prevents billing disputes.
IS 808 tables feed directly into structural calculations. The moment of inertia (Iₓₓ, Iyy), section modulus (Zₓₓ), and radius of gyration (rₓₓ, ryy) values from IS 808 are used in IS 800 (steel design code) calculations for beams, columns, and frames.
Every hot-rolled section covered by IS 808 — shape, designation, uses, and available sizes in India
I-shaped cross-section with flanges and web. The primary beam for spanning loads. High moment of inertia about the major (XX) axis makes it ideal for bending. Most widely used structural section in India for floors, roofs, and bridges.
C-shaped (or U-shaped) cross-section with one open face. Used for purlins, secondary beams, side rails, crane rails, and light structural frames. Often used back-to-back (twin channel) to form a box section for increased torsional stiffness.
L-shaped section, available as equal leg (both legs same length) and unequal leg (different leg lengths). The most versatile and economical structural section. Used extensively for bracings, trusses, towers, transmission line structures, and light frames.
Wide-flange I-section with heavier flanges and web than ISMB. Provides higher bending strength and is also used as a column section. The wide flanges give better resistance to lateral-torsional buckling. Used for heavily loaded primary beams and combined beam-column members.
Similar to ISMB but with wider, parallel flanges (no taper on flange). The parallel flanges make bolted connections more convenient. Widely used in industrial buildings and bridges where flange width provides better connection flexibility. Comparable to universal beams (UB) used internationally.
Box-like H-section with nearly equal flange width and depth — designed specifically as column sections where equal strength is needed about both axes. The nearly square shape provides similar moment of inertia about both XX and YY axes, making it efficient for column loading with biaxial bending.
Decode any IS 808 section name in seconds — three examples
ISMB 300 → I-beam, 300 mm deep, 140 mm flange width, web 7.5 mm, flange 12.4 mm, 46.1 kg/m (IS 808)
ISMC 150 → C-channel, 150 mm deep, 75 mm flange width, web 5.7 mm, flange 9.0 mm, 16.4 kg/m (IS 808)
ISA 75×50×6 → Unequal angle, long leg 75 mm, short leg 50 mm, 6 mm thick, 5.65 kg/m (IS 808). For equal angles: ISA 75×75×8 → both legs 75 mm, 8 mm thick.
What each column in the IS 808 tables means — and how they are used in structural design
Complete IS 808 reference — depth, flange width, web thickness, mass per metre for all ISMB sizes
| Section | Depth D (mm) | Flange Width B (mm) | Web Thick. tw (mm) | Flange Thick. tf (mm) | Area (cm²) | Mass (kg/m) | Iₓₓ (cm⁴) | Zₓₓ (cm³) | 6m Piece (kg) |
|---|---|---|---|---|---|---|---|---|---|
| ISMB 100 | 100 | 75 | 4.0 | 7.2 | 11.33 | 8.90 | 257.5 | 51.5 | 53.4 |
| ISMB 125 | 125 | 75 | 4.4 | 7.6 | 13.16 | 13.10 | 449.8 | 72.0 | 78.6 |
| ISMB 150 | 150 | 80 | 4.8 | 7.6 | 15.57 | 14.90 | 726.4 | 96.9 | 89.4 |
| ISMB 175 | 175 | 90 | 5.5 | 8.6 | 20.29 | 19.30 | 1264 | 144 | 115.8 |
| ISMB 200 | 200 | 100 | 5.7 | 10.8 | 32.33 | 25.40 | 2235 | 224 | 152.4 |
| ISMB 225 | 225 | 110 | 6.5 | 11.8 | 38.67 | 30.40 | 3441 | 306 | 182.4 |
| ISMB 250 | 250 | 125 | 6.9 | 12.5 | 47.55 | 37.30 | 5132 | 411 | 223.8 |
| ISMB 300 | 300 | 140 | 7.5 | 12.4 | 58.83 | 46.10 | 8603 | 574 | 276.6 |
| ISMB 350 | 350 | 140 | 8.1 | 14.2 | 66.71 | 52.40 | 13630 | 779 | 314.4 |
| ISMB 400 | 400 | 140 | 8.9 | 16.0 | 78.46 | 61.50 | 20458 | 1022 | 369.0 |
| ISMB 450 | 450 | 150 | 9.4 | 17.4 | 92.27 | 72.40 | 30390 | 1351 | 434.4 |
| ISMB 500 | 500 | 180 | 10.2 | 17.2 | 110.74 | 86.90 | 45218 | 1808 | 521.4 |
| ISMB 550 | 550 | 190 | 11.2 | 19.3 | 132.11 | 103.70 | 64893 | 2361 | 622.2 |
| ISMB 600 | 600 | 210 | 12.0 | 20.8 | 156.21 | 122.60 | 91813 | 3061 | 735.6 |
* IS 808:2021 values. Highlighted rows (ISMB 175, 250, 400, 550) are most commonly stocked across India. Mass billed at theoretical 7.85 g/cm³. For BOQ, always use IS 808 mass — not calculator estimates.
Complete IS 808 reference for all standard channel sections
| Section | Depth D (mm) | Flange B (mm) | Web tw (mm) | Flange tf (mm) | Area (cm²) | Mass (kg/m) | Iₓₓ (cm⁴) | Cyy (cm) | 6m Piece (kg) |
|---|---|---|---|---|---|---|---|---|---|
| ISMC 75 | 75 | 40 | 4.4 | 7.3 | 8.68 | 6.80 | 75.8 | 1.22 | 40.8 |
| ISMC 100 | 100 | 50 | 4.7 | 7.5 | 11.70 | 9.20 | 187.6 | 1.47 | 55.2 |
| ISMC 125 | 125 | 65 | 5.0 | 8.1 | 16.60 | 13.10 | 424.6 | 1.94 | 78.6 |
| ISMC 150 | 150 | 75 | 5.7 | 9.0 | 20.88 | 16.40 | 779.4 | 2.17 | 98.4 |
| ISMC 175 | 175 | 75 | 6.0 | 10.2 | 24.38 | 19.10 | 1222 | 2.07 | 114.6 |
| ISMC 200 | 200 | 75 | 6.2 | 11.4 | 28.21 | 22.10 | 1820 | 1.97 | 132.6 |
| ISMC 225 | 225 | 80 | 6.5 | 12.4 | 33.01 | 25.90 | 2694 | 2.11 | 155.4 |
| ISMC 250 | 250 | 82 | 7.2 | 14.1 | 40.93 | 32.20 | 3828 | 2.16 | 193.2 |
| ISMC 300 | 300 | 90 | 7.8 | 13.6 | 46.33 | 36.30 | 6362 | 2.18 | 217.8 |
| ISMC 350 | 350 | 100 | 8.1 | 13.5 | 53.66 | 42.10 | 10008 | 2.40 | 252.6 |
| ISMC 400 | 400 | 100 | 8.8 | 15.3 | 63.83 | 50.10 | 15082 | 2.42 | 300.6 |
* IS 808:2021 ISMC values. Highlighted rows are most commonly stocked. Cyy = centroid distance from back of web. Used as back-to-back twin channels by doubling mass and adjusting Iₓₓ.
Most commonly used equal leg angle sizes with IS 808 mass per metre
| Section | Leg A (mm) | Thickness t (mm) | Area (cm²) | Mass (kg/m) | Iₓₓ (cm⁴) | Cₓₓ (cm) | 6m Piece (kg) | Common Use |
|---|---|---|---|---|---|---|---|---|
| ISA 25×25×3 | 25 | 3 | 1.42 | 1.11 | 0.69 | 0.72 | 6.7 | Light bracing, light frames |
| ISA 30×30×3 | 30 | 3 | 1.74 | 1.36 | 1.22 | 0.83 | 8.2 | Light bracing |
| ISA 40×40×4 | 40 | 4 | 3.07 | 2.42 | 3.59 | 1.09 | 14.5 | Medium bracing, secondary frames |
| ISA 45×45×5 | 45 | 5 | 4.30 | 3.38 | 6.35 | 1.25 | 20.3 | Medium structural bracing |
| ISA 50×50×5 | 50 | 5 | 4.80 | 3.77 | 8.86 | 1.36 | 22.6 | Most common — tower, truss bracing |
| ISA 50×50×6 | 50 | 6 | 5.69 | 4.47 | 10.26 | 1.40 | 26.8 | Heavier bracing frames |
| ISA 60×60×6 | 60 | 6 | 6.91 | 5.42 | 18.07 | 1.64 | 32.5 | Structural bracing, transmission |
| ISA 65×65×8 | 65 | 8 | 9.76 | 7.67 | 30.63 | 1.83 | 46.0 | Heavy bracing, tension members |
| ISA 75×75×6 | 75 | 6 | 8.69 | 6.82 | 38.78 | 2.03 | 40.9 | Trusses, medium structural |
| ISA 75×75×8 | 75 | 8 | 11.38 | 8.96 | 49.52 | 2.09 | 53.8 | Heavy structural bracing |
| ISA 100×100×8 | 100 | 8 | 15.44 | 12.10 | 120.6 | 2.71 | 72.6 | Heavy trusses, industrial frames |
| ISA 100×100×10 | 100 | 10 | 19.03 | 14.90 | 146.3 | 2.77 | 89.4 | Heavy trusses, main members |
| ISA 110×110×10 | 110 | 10 | 21.07 | 16.60 | 198.4 | 3.02 | 99.6 | Large industrial structures |
| ISA 130×130×10 | 130 | 10 | 25.12 | 19.70 | 331.4 | 3.52 | 118.2 | Heavy industrial structural |
| ISA 150×150×12 | 150 | 12 | 34.77 | 27.30 | 664.3 | 4.10 | 163.8 | Very heavy structural frames |
* IS 808:2021 ISA equal angle values. Highlighted rows are the most commonly stocked across Indian steel service centres. Cₓₓ = centroid distance from back of leg. Standard lengths: 6 m and 12 m.
How to use IS 808 tables to estimate structural steel weight for a BOQ
IS 808 mass: 25.4 kg/m
Per piece: 25.4 × 6 = 152.4 kg
Total: 152.4 × 8 = 1,219.2 kg
IS 808 mass: 16.4 kg/m
Per piece: 16.4 × 3 = 49.2 kg
Total: 49.2 × 20 = 984.0 kg
IS 808 mass: 4.47 kg/m
Per piece: 4.47 × 2.5 = 11.2 kg
Total: 11.2 × 16 = 178.8 kg
Primary beams: 1,219.2 kg
Secondary beams: 984.0 kg
Bracing: 178.8 kg
Grand Total: 2,382 kg = 2.382 MT
At ₹65/kg → ₹1,54,830
Write "ISMB 200 IS 808:2021, IS 2062 E250 grade, 6m lengths with MTC" on every purchase order. Quoting the IS 808 number ensures the supplier provides the correct theoretical weight reference for billing. Indian steel is invoiced at IS 808 theoretical mass per metre — if the section name is ambiguous, billing disputes arise.
Online calculators (including this site) derive weight from cross-section geometry × density — useful for quick estimation. But for final BOQs, purchase orders, and billing verification, always use the published IS 808 table mass. The IS 808 value is the legal reference that matches supplier invoices, which are based on the same IS 808 tables.
For all structural IS 808 sections (ISMB, ISMC, ISA), insist on an MTC from the primary mill (SAIL Bhilai/Rourkela, Tata Steel, JSPL, JSW) with every consignment. The MTC certifies: section designation, heat number, IS 2062 grade compliance, chemical composition, mechanical test results, and IS 808 dimensional compliance. Critical for structural applications.
ISMB for primary spanning members (floors, roofs, bridges) where bending is the main design action. ISMC for secondary members (purlins, side rails, secondary beams, crane gantry rails) and back-to-back box columns. ISA for bracings, tension members, transmission towers, and connections. Mixing these roles is a common design error in small Indian fabrication projects.
Primary mill ISMB (SAIL, Tata): ₹60–70/kg depending on size and region. ISMC: ₹62–72/kg. ISA equal angle: ₹58–68/kg. Secondary/re-roller material is ₹5–10/kg cheaper but carries higher dimensional and grade compliance risk. All prices ex-stockist, exclusive of GST (18%). Prices fluctuate with global scrap and coking coal markets — verify current rates before finalising BOQs.
IS 808 specifies shape (dimensions, mass, sectional properties). IS 2062 specifies steel grade (yield strength, tensile strength, carbon content, weldability). You need both on every structural PO. A section made to IS 808 dimensions but from inferior steel (lower yield strength than E250) is dimensionally correct but structurally inadequate. The MTC confirms both compliance in one document.