This specification covers iron-chromium-nickel alloy, stainless steel castings intended for particularly severe corrosive applications.

This specification requires postweld heat treatment of all weld repairs affecting surfaces intended to be wetted by the corrosive medium. For applications for which postweld heat treatment is not considered mandatory for retention of acceptable corrosion resistance, refer to AASHTO M 163M/M 163.

For general corrosion-resistant alloy castings, reference should be made to AASHTO M 163M/M 163. For general heat-resistant alloy castings, reference should be made to ASTM A297/A297M. For nickel-base alloy castings, refer to ASTM A494/A494M.

The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text, the inch-pound units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard. SI units are applicable for material ordered to M 285M and inch-pound units for material ordered to M 285.