60A18 Type "A" sprockets are hubless sprockets with a stock bore that is made to ANSI B29.1 standards. These are also commonly referred to as plate sprockets. Our 60A18 sprockets are manufactured from 1045CD carbon steel and have a black oxide finish. The teeth are hardened to help minimize tooth wear. Type A sprockets are great for welding onto a shaft or machining in bolt holes for mounting.