ASME SA573/SA573M is is Standard Specification for Standard Specification for Structural Carbon Steel Plates of Improved Toughness.It 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.ASME SA573/SA573M Standard main steel grade:ASME SA573Grade 58,65,70(SA573GR58,SA573GR65,SA573GR70)