ASTM A242 is the defining standard for this material. Additionally, the UNS number is K11510. ASTM A242 Type 1 and A242 Type 2 plates are available.
| Grade | C | Mn | P | S | Cu |
| A242 TYPE 1 | 0.15 Max | 1.00 Max | 0.15Max | 0.02 Max | 0.20 Min |
Heat analysis shall be performed wherein steel specimens shall conform to required chemical compositions of carbon, manganese, phosphorus, sulfur, and copper.
| ASTM A242 | Plates and Bars | Structural Shapes | ||||
| For thickness 3/4 in. (20mm), and under | For thickness 3/4 to 1.5 in. (20 to 40mm) | For thickness 1.5 to 4 in.40 to 100mm) | For range or leg thickness 1.5 in. (40mm), and under | For range thickness over 1.5 in. (40mm) to 2 in. (50mm) | For range thickness over 2 in. (50mm) | |
| Tensile Strength, ksi (MPa) min. | 70 (480) | 67 (460) | 63 (435) | 70 (485) | 67 (460) | 63 (435) |
| Yield Strength, ksi (MPa) min. | 50(345) | 46(315) | 42(290) | 50(345) | 46(315) | 42(290) |
| Elongation in 8 in. (200). min. % | 18 | 18 | 18 | 18 | 18 | 18 |
| Elongation in 2 in. (50) min. % | 21 | 21 | 21 | 21 | 21 | 21 |
The atmospheric corrosion resistance of A242 steel in most environments is substantially better than that of carbon structural steel with or without copper addition. When properly exposed to the atmosphere, this steel can be used bare (unpainted) for many applications. When the steel is to be welded, ASTM A242 is presupposed that a welding procedure suitable for the grade of steel and intended use or service will be utilized.
