ASTM A573/A573M Standard Specification for Structural Carbon Steel Plates of Improved Toughnessl.ASTM A573/A573M specification covers structural quality carbon-manganese-silicon steel plates in three tensile strength ranges intended primarily for service at atmospheric temperatures where improved notch toughness is important. ASTM A573/A573M Standard main steel grade:ASTM A573Grade 58,65,70(A573GR58,A573GR65,A573GR70)