G40.21 Types
| Type W | Weldable Steel |
|---|---|
| Type WT | Weldable Notch Tough Steel (low temperature) |
| Type R | Atmospheric Corrosion Resistant Steel |
| Type A | Atmospheric Corrosion Resistant Weldable Steel |
| Type AT | Atmospheric Corrosion Resistant Weldable Notch Tough Steel |
| Type Q | Quenched and Tempered Low Alloy Steel Plate Steel |
| Type QT | Quenched and Tempered Low Alloy Notch Tough Steel Plate |