Radial Internal Clearance

Proper internal clearance is important for optimal bearing life. It allows for thermal expansion and slight misalignment of the inner and outer rings.

The radial internal clearance for BL ball bearings is typically C3. Bearings can also be supplied in tighter clearances (C0) for applications that require less radial play, or in looser clearances (C4) for high temperature and specialized applications.

Minimum and maximum radial internal clearance (C3) and (C0) ranges for BL bearings are shown in the tables below.

Bore Diameter (d) Radial Internal Clearance (C3)
MM Inches MM Inches
Over Inc. Over Inc. Min. Max. Min. Max.
10 18 0.39 0.71 0.001 0.025 0.0004 0.001
18 24 0.71 0.95 0.012 0.028 0.0005 0.0011
24 30 0.95 1.18 0.012 0.028 0.0005 0.0011
30 40 1.18 1.58 0.013 0.033 0.0006 0.0013
40 50 1.57 1.97 0.014 0.036 0.0007 0.0014
50 65 1.97 2.56 0.018 0.043 0.0009 0.0017
65 80 2.56 3.15 0.02 0.051 0.001 0.002
80 100 3.15 3.94 0.024 0.058 0.0012 0.0023
100 120 3.94 4.72 0.028 0.066 0.0014 0.0026
Bore Diameter (d) Radial Internal Clearance (C0)
MM Inch MM Inch
Over Inc. Over Inc. Min. Max. Min. Max.
10 18 0.39 0.71 0.003 0.018 0.0001 0.007
18 24 0.71 0.95 0.005 0.02 0.0002 0.008
24 30 0.95 1.18 0.005 0.02 0.0002 0.008
30 40 1.18 1.58 0.006 0.02 0.0002 0.008
40 50 1.57 1.97 0.006 0.023 0.0002 0.009
50 65 1.97 2.56 0.008 0.028 0.0003 0.0011
65 80 2.56 3.15 0.01 0.03 0.0004 0.0012
80 100 3.15 3.94 0.012 0.036 0.0005 0.0014
100 120 3.94 4.72 0.015 0.041 0.0006 0.0016