ISMC 300 weight and dimensions
36.3 kg/m · 24.39 lb/ft
ISMC 300 is a 300 mm deep channel with a 90 mm flange, 7.8 mm web and 13.6 mm flange thickness. It weighs 36.3 kg per metre (24.39 lb/ft). It belongs to the ISMC medium weight channel series, Indian Standard (IS 808).
Many weight charts list ISMC 300 as 35.8 kg/m. That figure comes from the 1964 ISI handbook. The current standard, IS 808:2021, gives 36.3 kg/m (IS 808:1989: 36.3 kg/m).
ISMC 300 weight calculator
Weight of standard lengths
| Pieces | 6 m each (kg) | 12 m each (kg) |
|---|---|---|
| 1 | 217.8 | 435.6 |
| 5 | 1,089.0 | 2,178.0 |
| 10 | 2,178.0 | 4,356.0 |
| 20 | 4,356.0 | 8,712.0 |
| 50 | 10,890.0 | 21,780.0 |
Pieces per tonne
| 6 m lengths per metric tonne | 4.6 |
| 12 m lengths per metric tonne | 2.3 |
| Length per tonne | 27.5 m |
Useful for converting a tonnage order into a number of bars.
Surface area for painting
| Per metre of length | 0.933 m²/m |
| Per foot of length | 3.06 ft²/ft |
| Per tonne of steel | 25.7 m²/t |
| A 12 m length | 11.20 m² |
Outside perimeter × length, all faces, calculated from the dimensions. Use it to estimate paint, primer, fireproofing or galvanizing quantities.
Cross-section
Drawn to scale. Dimensions in mm.
Dimensions
| Depth h | 300 mm | 11.811 in |
| Flange width b | 90 mm | 3.543 in |
| Web thickness tw | 7.8 mm | 0.307 in |
| Flange thickness tf | 13.6 mm | 0.535 in |
| Root radius r | 13 mm | 0.512 in |
| Toe radius r2 | 3.2 mm | 0.126 in |
| Flange slope (deg) | 96° | |
| Mass | 36.3 kg/m | 24.39 lb/ft |
Section properties
| Property | Value | Unit |
|---|---|---|
| Area | 46.20 | cm² |
| Moment of inertia Ix | 6,400 | cm⁴ |
| Moment of inertia Iy | 311 | cm⁴ |
| Elastic modulus Zx | 427 | cm³ |
| Elastic modulus Zy | 46.80 | cm³ |
| Plastic modulus Zpx | 501 | cm³ |
| Plastic modulus Zpy | 91.90 | cm³ |
| Radius of gyration rx | 11.70 | cm |
| Radius of gyration ry | 0.26 | cm |
| Torsion constant J | 21.70 | cm⁴ |
Equivalent sections in other standards
The closest sections by depth and weight. They are not direct substitutes: check bending, buckling and connection details before swapping one for another.
ISMC 300 and its closest equivalents, drawn over each other at the same scale.
| Section | Standard | Depth (mm) | kg/m | Weight vs ISMC 300 |
|---|---|---|---|---|
| ISMC 300 | IS | 300 | 36.3 | — |
| UPN 300 | EN | 300 | 46.13 | +27.1% |
| UPN 280 | EN | 280 | 41.91 | +15.5% |
| C12x25 | AISC | 305 | 37.00 | +1.9% |
| C12x20.7 | AISC | 305 | 30.80 | -15.2% |
ISMC series weights
Next lighter: ISMC 250 (30.6 kg/m). Next heavier: ISMC 350 (42.7 kg/m).
Stiffness and strength per kilogram
The elastic section modulus Zx governs bending strength. Dividing it by the weight shows how efficiently each size uses its steel: higher is better when weight is the cost driver.
| Section | kg/m | Ix (cm⁴) | Zx (cm³) | Zx per kg/m |
|---|---|---|---|---|
| ISMC 200 | 22.30 | 1,820 | 182.0 | 8.16 |
| ISMC 225 | 26.10 | 2,700 | 240.0 | 9.20 |
| ISMC 250 | 30.60 | 3,820 | 306.0 | 10.00 |
| ISMC 300 | 36.30 | 6,400 | 427.0 | 11.76 |
| ISMC 350 | 42.70 | 10,000 | 575.0 | 13.47 |
| ISMC 400 | 50.10 | 15,100 | 758.0 | 15.13 |
Full table: ISMC channel weight chart (PDF).
How the weight is calculated
Mass per metre = cross-sectional area × density of steel = 46.20 cm² × 0.785 kg/(cm²·m) = 36.27 kg/m.
Rolled sections are made to a nominal mass, and the actual mass can differ by a few percent within the tolerances of IS 1852. For purchasing, invoicing by weight or checking deliveries, use the producer's stated mass.
Typical uses
Channels are used as purlins, girts, stair stringers, trimmers, frames and bracing, and back to back as built-up columns.
Frequently asked questions
What is the weight of ISMC 300 per metre?
ISMC 300 weighs 36.3 kg/m, which is 24.39 lb/ft.
How much does a 6 m or 12 m length of ISMC 300 weigh?
A 6 m length weighs about 217.8 kg and a 12 m length about 435.6 kg.
Why do some weight charts show 35.8 kg/m for ISMC 300?
35.8 kg/m is the value in the 1964 ISI handbook SP 6(1). IS 808 was revised in 1989 and the section dimensions changed; IS 808:2021 gives 36.3 kg/m. Many charts still copy the old figure, so confirm which standard your supplier rolls to.
What is the equivalent of ISMC 300 in other standards?
By depth and weight the closest match is UPN 300 (46.13 kg/m, 300 mm deep). Check section properties before substituting one for the other.
Source: IS 808:2021; earlier values from IS 808:1989 and SP 6(1):1964. Values are nominal; verify with the producer before ordering.