ASTM A403 Standard Specification for Wrought Austenitic Stainless Steel Piping Fittings

ASTM A403 Standard Specification for Wrought Austenitic Stainless Steel Piping Fittings

ASTM A403 Standard specifification covers wrought stainless steel fifittings for pressure piping applications.

Several grades of austenitic stainless steel alloys are included in this specifification Grades are designated with a prefifix, WP or CR, based on the applicable ASME or MSS dimensional and rating standards, respectively. 

For each of the WP stainless grades, several classes of fifittings are covered, to indicate whether seamless or welded construction was utilized. Class designations are also utilized to indicate the nondestructive test method and extent of nondestructive examination (NDE). Table 1 is a general summary of the fifitting classes applicable to all WP grades of stainless steel covered by this specifification. There are no classes for the CR grades. Specifific requirements are covered elsewhere. 

This specifification is expressed in both inch-pound units and in SI units. However, unless the order specififies the applicable “M” specifification designation (SI units), the material shall be furnished to inch-pound units. 

The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specififi- cation. 

This specifification does not apply to cast steel fifittings. Austenitic stainless steel castings are covered in Specififications A 351/A 351M, A 743/A 743M, and A 744/A 744M.