... , 1610, 1615, 2012, 2517, 3020, 3535, 4040, 4545, 5050.2. QD type: JA, SH, SDS, SD, SK, SF, E, F, J ... , M, N, P, W, S.3. Material: Steel, Cast iron,GG254. Surface treatment ... .4. OEM and Customized available with fast delivery. Taper bushing/QD taper bush