Question: what is the difference between malleable iron and steel?
Answer: Malleable iron fittings are lighter fittings in 150# and 300# pressure class. They are made for light industrial and plumbing use up to 300 psi. ... Forged fittings are made of A105 (carbon steel), stainless steel or nickel alloy. These fittings are thicker, heavier and are intended for heavy industrial use.