The term cast iron encompasses a family of ferrous alloys with a variety of metallurgical, mechanical, and physical properties. The chemical composition and welding requirements of the metals vary within the family. This document discusses the relative weldability of various types of cast irons and the filler metals and processes used to weld them. It recommends the steps for qualification of welding procedures, welding operators and welders, and requirements for the quality of welds. The terms welding procedure, welding operator, and welder, are used as defined in the latest edition of ANSI/AWS A3.0, Standard Welding Terms and Definitions.