This Standard sets forth the criteria to be used in the selection of materials for spacecraft and associated equipment and facilities so that failure resulting from stress-corrosion is prevented. Three categories of materials are listed in Tables 1, 2 and 3 of this Standard. They represent metal alloys with a high, moderate and low resistance to stress-corrosion cracking. The stress-corrosion susceptibility of alloys included in this Standard was determined at ambient temperature - by means of laboratory tests in which specimens were either sprayed with salt water or periodically immersed and withdrawn; by exposing specimens in sea coast or mild industrial