ASTM A588/A588M specification covers high-strength low-alloy structural steel shapes, plates, and bars for welded, riveted, or bolted construction but intended primarily for use in welded bridges and buildings where savings in weight or added durability are important. The atmospheric corrosion resistance of ASTM A588/A588M steel in most environments is substantially better than that of carbon structural steels with or without copper addition. When properly exposed to the atmosphere, ASTM A588/A588M steel is suitable for many applications in the bare (unpainted) condition. ASTM A588/A588M specification is limited to material up to 8 in. [200 mm] inclusive in thickness.
| Element/Composition, % | Carbon (C), max | Manganese (Mn), max | Phosphorus (P), max | Sulfur (S), max | Silicon (Si) | Nickel (Ni) | Chromium (Cr) | Molybdenum (Mo) | Copper (Cu), min | Vanadium (V) | Columbium (Nb) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| ASTM A588/A588M Grade A | 0.19 max | 0.80–1.25 | 0.04 max | 0.05 max | 0.30–0.65 | 0.40 max | 0.40–0.65 | ... | 0.25–0.40 | 0.02–0.10 | ... |
| ASTM A588/A588M Grade B | 0.20 max | 0.75–1.35 | 0.04 max | 0.05 max | 0.15–0.50 | 0.50 max | 0.40–0.70 | ... | 0.20–0.40 | 0.01–0.10 | ... |
| ASTM A588/A588M Grade C | 0.17 max | 0.50–1.20 | 0.04 max | 0.05 max | 0.25–0.50 | 0.40 max | 0.40–0.70 | 0.10 max | 0.30–0.50 | ... | 0.005–0.05B |
| Type | Tensile strength, min, ksi [MPa] | Yield point, min, ksi [MPa] | Elongation in 8 in. [200 mm], min, % | Elongation in 2 in. [50 mm], min, % | |
|---|---|---|---|---|---|
Plates and BarsA |
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| For thicknesses 3⁄4 in.[20 mm], andunder | 70 [485] | 50 [345] | 18B,C | 21B,C | |
| For thicknesses over3⁄4 to 11⁄2 in. [20 to 40 mm], incl | 67 [460] | 46 [315] | ... | 21B,C | |
| For thicknesses over11⁄2 to 4 in. [40 to 100 mm], incl | 63 [435] | 42 [290] | ... | 21B,C | |
| Structural Shapes | All | 70 [485] | 50 [345] | 18C | 21D |
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