BABBITT'S METAL, an alloy, invented by Isaac Babbitt, for the special purposes of machine bearings. A typical anti-fric tion alloy of this type contains 25 parts of tin, 2 parts of antimony and 0.5 part of copper. According to the British Admiralty speci fication for an anti-friction alloy in marine engines the metal should contain 2 to 7% of copper and 8 to 9% of antimony, the remainder being tin. Babbitt metal contains two inter-metal lic compounds SbSn and these comparatively hard con stituents are set in a soft plastic matrix containing the excess of tin. Alloys consisting of hard and soft constituents are of special value as anti-friction materials. (See ANTI-FRICTION METALS.)