Steel flange adaptor is a specialized fitting used in piping systems to connect pipes or other components that have different end types, such as a plain end or a grooved end, to a flanged end. These adaptors are made of steel, which provides strength, durability, and resistance to high pressures and temperatures.

Compared to cast iron flange adaptors, carbon steel flange adaptors can withstand higher pressures such as PN40, PN63 or PN100 which is impossible for cast iron flange adaptor to afford.