What is the difference between ASTM A516 Gr 70 plate and ASME SA 516 Gr 70 plate? In fact, the mechanical and chemical properties of the ASTM A516 Gr 70 plate and ASME SA 516 Gr 70 plate are identical. And it is the producer of the standard that is the key difference.

ASTM A516 Gr 70 plate is under ASTM standard. ASTM, the American Society for Testing and Materials, produces standards that define limits and parameters on a product’s properties and the methods of testing those properties.

ASME SA 516 Gr 70 plate is under ASME standard. ASME, the American Society of Mechanical Engineers, specifies materials to be used in the manufacture and construction of particular items. The relevance of this to pressure vessels is that ASME publishes design codes and standards for the manufacture of vessels and within these a particular material standard will be endorsed.

ASME “acquires” ASTM specifications in this way and its pressure vessel code committee assigns an “S” to the relevant ASTM standard. So ASTM A516 Gr 70 plate becomes ASME SA 516 Gr 70 plate when ASME acquires it.