This 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 this steel in most environments is substantially better than that of carbon structural steels with or without copper addition. When properly exposed to the atmosphere, this steel is suitable for many applications in the bare (unpainted) condition. This specification is limited to material up to 8 in. [200 mm] inclusive in thickness.
Grades | Description |
---|---|
Grade A | - |
Grade B | - |
Grade K | - |
Grade | CarbonA | ManganeseA | Phosphorus | Sulfur | Silicon | Nickel | Chromium | Molybdenum | Copper | Vanadium | Columbium |
---|---|---|---|---|---|---|---|---|---|---|---|
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 | - |
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 | - |
Grade K | 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 |
Product Form | Thickness |
Tensile strength,min: ksi [MPa] |
Yield strength,min: ksi [MPa] |
Elongation in 8 in. [200 mm] min, % | Elongation in 2 in. [50 mm] min, % |
---|---|---|---|---|---|
Plates and Bars | |||||
For Thicknesses 4 in. [100 mm] and Under | 70 [485] | 50 [345] | 18B,C | 21B,C | |
For Thicknesses Over 4 in. [100 mm] to 5 in. [125 mm] incl | 67 [460] | 46 [315] | ... | 21B,C | |
For Thicknesses Over 5 in. [125 mm] to 8 in.[200 mm] incl | 63 [435] | 42 [290] | ... | 21B,C | |
Structural Shapes | All | 70 [485] | 50 [345] | 18C | 21D |