Can A193 Grade B7M bolts be hot-dip galvanized?
A193 Grade B7M is a grade variation of the common A193 Grade B7 used in high-temperature, high-pressure applications. Nowhere in the A193 specification does it discuss whether or not A193B7M fasteners can be galvanized. In theory, there is nothing preventing someone from galvanizing the material, however, the application in which these bolts are intended to be used makes galvanizing these bolts unusual. As stated above, the A193 specification is designed for fasteners used in high-temperature, high-pressure situations. The intended use for A193B7M fasteners is for situations of even greater temperatures than A193B7 can withstand. Since the intended temperatures these fasteners are being used in would well exceed the melting point of a galvanized coating, it is arguable that the fasteners would never need to be galvanized because the coating would be rendered useless once installed.