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 corrosion-resistant applications, and Section B covers the heat-resistant grades. The distinction between these groups is defined arbitrarily as follows: corrosion-resistant 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. The data have been so arranged that ready comparison of properties may be made for the various alloys. As previously indicated, a large amount of data has been reviewed and the values which have been selected for inclusion herein represent tha most authoritative information presently available on the alloys covered. In most instances single figures rather than ranges have been used to describe the several properties of these alloys. These figures are representative values and are not minimum or average values. In general they have been selected from data representative of current commercial practice. The values in these tables should not be considered as specification figures: the latter may be found in the appropriate A.S.T.M. standards for this class of materials.