ASTM A234 specificationem habet multa grades, ut WPB, WPC, WP5, WP9 WP11, WP12, WP22, WP91 et ita in.
In his vexillum gradu WPB est maxime commune materia usus est medium et altum temperatus pipelines. W significat Weldable, P est pressura, B est gradu B, ad minimum cede vires.