The present classification has been prepared from data submitted by the producers of alloy castings, and covers those alloys of widest commercial importance. For purposes of identification the alloys are listed in accordance with the designations established by the Alloy Casting Institute, and, where possible, the appropriate A.S.T.M. designations and grades are also shown. The alloys have been divided into two main groups: Section A covers the alloys used for corrosionresistant applications, and Section B covers the heat-resistant grades. The distinction between these groups is denned arbitrarily as follows: corrosionresistant alloys are those which normally operate in contact with corrosive agents at a metal temperature less than 1200 F.; heat-resistant alloys are those which normally operate under conditions where the metal temperature is in excess of 1200 F.