What is MS ISMB?
MS ISMB stands for Mild Steel Indian Standard Medium Beam. It is an I-section structural steel beam manufactured as per Indian Standards and widely used in construction and heavy structural fabrication.
The beam has an “I” shape cross-section, designed to provide high bending strength and load-bearing capacity with less material weight.
It is commonly called:
I Beam
RSJ (Rolled Steel Joist)
Medium Weight Beam
Material Composition (Typical Mild Steel)
| Element | Percentage (%) |
|---|---|
| Carbon (C) | 0.15 – 0.25% |
| Manganese (Mn) | 0.30 – 0.60% |
| Sulfur (S) | ≤ 0.05% |
| Phosphorus (P) | ≤ 0.04% |
| Iron (Fe) | Balance |
Mechanical Properties
| Property | Value |
|---|---|
| Yield Strength | 250 MPa (Fe 250) |
| Tensile Strength | 410 – 540 MPa |
| Density | 7,850 kg/m³ |
| Modulus of Elasticity | 200 GPa |
Common Grades:
IS 2062 E250
IS 2062 E350
Standard ISMB Sizes (As per IS 808)
| Designation | Depth (mm) | Weight (kg/m) |
|---|---|---|
| ISMB 100 | 100 mm | 11.5 kg/m |
| ISMB 125 | 125 mm | 13.0 kg/m |
| ISMB 150 | 150 mm | 14.9 kg/m |
| ISMB 200 | 200 mm | 25.4 kg/m |
| ISMB 250 | 250 mm | 37.3 kg/m |
| ISMB 300 | 300 mm | 44.2 kg/m |
| ISMB 350 | 350 mm | 52.4 kg/m |
| ISMB 400 | 400 mm | 61.6 kg/m |
| ISMB 450 | 450 mm | 72.4 kg/m |
| ISMB 500 | 500 mm | 86.9 kg/m |
| ISMB 600 | 600 mm | 122.6 kg/m |