... interchangeablity & high strength 3.Smooth surface Taper Bush:1. European Standard Type: 1008, 1108, 1210, 1215, 1310, 1610, 1615, 2012, 2517, 3020 ... , 3535, 4040, 4545, 5050.2. QD type: JA, SH, SDS, SD, SK, SF, E, F, J, M ... .3. Material: Steel, Cast iron4. Surface treatment: black, phosphateFeatures:1. Standard method for measureing keyseat depth.2. Excellent and high quality ...