... closure: Open ball bearing, Z, ZZ, RS, 2RS, 2RZ Ball bearings snap ring: N, NR Tolerance codes: ABEC-1, ABEC-3, ABEC-5 ... C3, C4, C5 Ball bearings material: AISI52100, AISI440C, AISI304, AISI316, ceramic Retainer: PTFE, nylon, or stainless steel Hardness for rings and ... balls: 59 - 63HRC Ball bearings bore size: 1 - 200mmBecause of ...