ASTM A709/A709M Standard Specification for Structural Steel for Bridges.ASTM A709/A709M specification covers carbon and high-strength low alloy steel structural shapes, plates and bars, and quenched and tempered alloy steel for structural plates intended for use in bridges.ASTM A709/A709M Standard main steel grade:ASTM A709Grade36,50,50S,50W,HPS50W(A709GR36,A709GR50,A709GR50S,A709GR50W,A709GRHPS50W)