Rationale

ASTM A320/A320M Table 5 contains an editorial inconsistency regarding the marking requirements for Class 2 stainless steel grades. Specifically, Table 5 omits the underline designation associated with Class 2 grades. The applicable Class 2 grades in ASTM A320/A320M and ASTM A193/A193M are equivalent with respect to chemistry, mechanical properties, heat treatment condition, and metallurgical requirements. Therefore, the marking requirements should also remain consistent to avoid unnecessary confusion for manufacturers, inspectors, and end users