Oldham couplings are easy to use 3-part couplings utilizing wear discs providing generous radial compensation. The discs are the sacrificial elements and are replaceable at low cost in the event of wear or breakage. The 4 hub styles and 2 disc materials that comprise the range are fully interchangeable within each of the 9 sizes available. This part is the hub only, a complete coupling consists of two hubs and a torque disc.