ASTM A572 covers five grades of high strength, low-alloy structural steel shapes, plates, and bars. All grades are intended for riveted, bolted, or welded structures, with the exception that grades 60 and 65 are not intended for welded bridge applications.
A572 Mechanical Requirements
| Grade | Yield, min ksi | Tensile, min ksi | Elongation, min % in 8” | Elongation, min % in 2” |
|---|
| 42 | 42 | 60 | 20 | 24 |
| 50 | 50 | 65 | 18 | 21 |
| 55 | 55 | 70 | 17 | 20 |
| 60 | 60 | 75 | 16 | 18 |
| 65 | 65 | 80 | 15 | 17 |
A572 Chemical Requirements
| Grade | Maximum Diameter, inches | Carbon, max% | Manganese, max% | Phosphorus, max% | Sulfur, max% | Silicon, max% |
|---|
| 42 | 6 | 0.21 | 1.35 | 0.04 | 0.05 | 0.40 |
| 50 | 4 | 0.23 | 1.35 | 0.04 | 0.05 | 0.40 |
| 55 | 2 | 0.25 | 1.35 | 0.04 | 0.05 | 0.40 |
| 60 | 1-1/4 | 0.26 | 1.35 | 0.04 | 0.05 | 0.40 |
| 65 | ½ to 1-1/4 | 0.23 | 1.65 | 0.04 | 0.05 | 0.40 |
| 65 | Below ½ | 0.26 | 1.35 | 0.04 | 0.05 | 0.40 |
| This abridged table shows only the chemical requirements for bars. The complete table including shapes and plates can be found in the ASTM standard at www.astm.org |
Alloy Content
In addition to the chemical requirements above, the material shall also contain enough alloying elements to meet the requirements of one of the below alloy types.
| Type | Elements | Heat Analysis, % |
|---|
| 1 | Columbium | 0.005 – 0.05 |
| 2 | Vanadium | 0.01 – 0.15 |
| 3 | Columbium | 0.005 – 0.05 |
| Vanadium | 0.01 – 0.15 |
| Columbium plus Vanadium | 0.02 – 0.15 |
| 5 | Titanium | 0.006 – 0.04 |
| Nitrogen | 0.003 – 0.015 |
| Vanadium | 0.06 max |
