Table4　　Single Bearing Vibration Speed Grade Can Not Be Over The Following Values(dB) mm Diameter Series(1) Diameter Series(2) Diameter Series(3) Bore diameter Z1 Z2 Z1 Z2 Z3 Z1 Z2 Z3 4 34 32 35 32 30 36 33 31 5 36 34 37 34 32 37 35 33 6 36 34 37 34 32 37 35 33 7 38 35 38 36 34 - - - 8 38 35 38 36 34 - - - 9 40 36 40 37 35 - - - 10 42 38 42 39 35 44 40 37 12 43 39 43 39 35 45 40 37 15 44 40 44 41 36 46 42 38 17 44 40 45 41 36 47 42 38 20 45 41 46 42 38 48 43 39 25 46 42 47 43 40 49 44 41 30 47 43 48 44 41 50 45 42 35 49 45 50 46 43 52 47 44 40 51 46 52 47 44 54 49 45 45 53 48 54 49 46 56 51 47 50 54 50 55 51 48 57 53 49 55 56 52 57 53 50 59 54 51 60 58 54 59 54 51 61 56 53 65 48 46 49 47 42 50 48 43 70 49 47 50 48 43 51 49 44 75 50 48 51 49 44 52 50 45 80 51 49 52 50 45 53 51 46 85 52 50 53 51 46 55 52 47 90 53 52 55 53 48 57 54 49 95 55 54 57 55 50 59 56 51 100 57 56 59 57 52 61 58 53