ASTM A588
Data verifiedASTM A588 is the American HSLA weathering steel specification — the 50 ksi structural grade whose Cu-Cr-Ni alloying gives roughly four times the atmospheric corrosion resistance of plain carbon steel. Unpainted A588 bridges are a standard sight across North America.
Chemical composition
| Element | Content (%) |
|---|---|
| C | ≤0.19 (Gr.A) |
| Si | 0.30–0.65 (Gr.A) |
| Mn | 0.80–1.25 (Gr.A) |
| P | ≤0.040 |
| S | ≤0.050 |
| Cr | 0.40–0.65 (Gr.A) |
| Ni | ≤0.40 (Gr.A) |
| Cu | 0.25–0.40 (Gr.A) |
| V | 0.02–0.10 (Gr.A) |
Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.
Properties
| Yield strength | ≥345 MPa (≤100 mm) |
| Tensile strength | ≥485 MPa (≤100 mm) |
| Density | 7.85 g/cm³ |
Heat treatment
Supplied as-rolled or normalized; atmospheric corrosion resistance index ≥6.0 per ASTM G101.
Equivalent grades
| Standard | Designation |
|---|---|
| din | S355J2W (near) |
| aisi | A588 Gr.A |
| gb | Q355NH (near) |
Compare side by side: ASTM A588 vs Corten B · ASTM A588 vs SPA-H
Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.
Applications & Processing
Applications: Highway bridges, building structures, towers, unpainted outdoor steelwork.
Processing: Use weathering-grade electrodes for exposed welds; observe the same no-standing-water detailing rules as all weathering steels.
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Ask for a quotationVisit NasteelSource: ASTM A588 published ranges (Grade A) · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.