GOST 380-2005
5SP Steel Billet (St5sp)
5SP (St5sp) is a higher-carbon semi-killed structural steel with increased tensile strength compared to 3SP. It is specified for applications requiring superior load-bearing capacity, including heavy structural elements and industrial machinery parts.
Chemical Composition
| Element | Symbol | Min % | Max % |
|---|---|---|---|
| Carbon | C | 0.28 | 0.37 |
| Manganese | Mn | 0.50 | 0.80 |
| Silicon | Si | 0.05 | 0.17 |
| 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 | 490–630 MPa |
| Yield Strength (min) | 285 MPa |
| Elongation (min) | 20% |
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
Heavy structural sections (H-beams, I-beams)
Rail and rail components
Industrial machinery parts
High-strength rebar
Structural plates and heavy bars