This is a very specific part for a mechanical repair. It's a Koyo IR-1916 inner ring for a needle roller bearing. In simple terms, needle roller bearings are super compact bearings that use lots of tiny, cylindrical rollers. Sometimes you buy just the outer 'drawn cup' part. This inner ring is the hardened and precision-ground raceway that the needles roll on. Its job is to provide a smooth, tough surface and it's designed for a loose transition fit on the shaft (meaning it slides on but isn't super tight). The dimensions are in inches: the inside diameter (ID) is 1-3/16\, the outside diameter (OD) is 1-1/2\, and it's 1\ wide. You would use this with a matching Koyo/Torrington drawn cup needle roller bearing (sold separately) to make a complete bearing assembly. This is for mechanics, machinists, or industrial maintenance folks who know exactly what they need. Always confirm these dimensions match your application.
