GOST 380-2005
3SP Steel Billet (St3sp)
3SP (St3sp) is a semi-killed structural carbon steel, widely used as feedstock for the production of construction rebar, wire rod, angles, channels, and other structural shapes. Its balanced carbon and manganese content provides excellent weldability and formability.
Chemical Composition
| Element | Symbol | Min % | Max % |
|---|---|---|---|
| Carbon | C | 0.14 | 0.22 |
| Manganese | Mn | 0.40 | 0.65 |
| Silicon | Si | 0.05 | 0.15 |
| Phosphorus | P | — | 0.04 |
| Sulfur | S | — | 0.05 |
| Chromium | Cr | — | 0.30 |
| Nickel | Ni | — | 0.30 |
| Copper | Cu | — | 0.30 |
Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength | 380–490 MPa |
| Yield Strength (min) | 245 MPa |
| Elongation (min) | 25% |
Dimensions & Tolerances
| Parameter | Specification |
|---|---|
| Cross Section | 100×100, 120×120, 130×130, 150×150 mm |
| Length | 6,000 / 9,000 / 12,000 mm |
| Corner Radius | 8–12 mm |
| Straightness | Max 5 mm/m |
| Tolerances | ±2.5% on cross-section |
Applications
Construction rebar (ribbed and plain)
Wire rod for nails, fencing, welding wire
Structural angles and channels
Flat bars and round bars
General structural steelwork