... .Good interchangeablity & high strength 3.Smooth surfaceTaper Bushing:1. European Standard Type: 1008, 1108, 1210, 1215, 1310, 1610, 1615, 2012, 2517 ... : Steel, Cast iron,GG254. Surface treatment: black, phosphateFeatures:1. Standard method for measureing keyseat depth.2. Excellent and high quality control, advanced ...