A572 Gr.50
Data verifiedASTM A572 Grade 50 is the standard American HSLA structural steel — the 50 ksi yield grade that replaced A36 in most US bridge and heavy construction work. Strength comes from Nb/V microalloying and grain refinement rather than carbon, so weldability remains good.
Chemical composition
| Element | Content (%) |
|---|---|
| C | ≤0.23 |
| Si | ≤0.40 |
| Mn | ≤1.35 |
| P | ≤0.035 |
| S | ≤0.045 |
| V | 0.01–0.15 (Type 2) |
Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.
Properties
| Yield strength | ≥345 MPa |
| Tensile strength | ≥450 MPa |
| Density | 7.85 g/cm³ |
Heat treatment
Supplied as-rolled or normalized; columbium/vanadium microalloyed for strength.
Equivalent grades
| Standard | Designation |
|---|---|
| din | S355J2 (near) |
| aisi | A572 Gr.50 |
| jis | SM520B (near) |
| gb | Q355B (near) |
Compare side by side: A572 Gr.50 vs S355J2 · A572 Gr.50 vs Q355B · A572 Gr.50 vs Q345B / 16Mn
Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.
Applications & Processing
Applications: Bridges, buildings, transmission towers, heavy equipment frames.
Processing: Good weldability with standard procedures; the usual upgrade path when A36 sections become too heavy.
FAQ
- A572 Gr.50 or S355J2 for export projects?
- They are the standard cross-pair: both ~350 MPa yield HSLA. S355J2 adds a −20 °C impact guarantee; A572 Gr.50 needs supplementary requirements to match that.
Need A572 Gr.50 from stock?
Steel.Wiki is sponsored by Shenzhen NewAsia Special Steel (Nasteel), a special-steel stockholder in Shenzhen stocking mold, tool and alloy steels with EN 10204 3.1 certification.
Ask for a quotationVisit NasteelSource: ASTM A572 published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.