Radial Internal Clearance for Ball Bearings

Precision Engineered Bearings

Radial Internal Clearance for Ball Bearings

Radial internal clearance provides for thermal expansion and slight misalignment of the inner and outer rings. Internal clearances for ball bearing units are typically greater than those of the same size of radial ball bearings. Proper internal clearance is important for optimal bearing life. Below are the most common clearance classifications for cylindrical bore insert bearings.

RADIAL INTERNAL CLEARANCE FOR CYLINDRICAL BORE BEARINGS

Bore Diameter d				C2 - Less than standard		C0 - Standard		C3 - Greater than Standard		C4 - Greater than C3
Millimeter		Inches		C L E A R A N C E — INCHES
Over	Inc.	Over	Inc.	Low	High	Low	High	Low	High	Low	High
—	2.5	—	0.984	—	.00024	.0001	.0004	.0004	.0007	—	—
2.5	10	0.984	.3937	—	.00028	.0001	.0005	.0003	.0009	.0006	.0011
10	18	.3937	.7087	—	.00035	.0001	.0007	.0004	.0010	.0007	.0013
18	24	.7087	.9449	—	.00039	.0002	.0008	.0005	.0011	.0008	.0014
24	30	.9449	1.1811	—	.00043	.0002	.0008	.0005	.0011	.0009	.0016
30	40	1.1811	1.5748	—	.00043	.0002	.0008	.0006	.0013	.0011	.0018
40	50	1.5748	1.9685	—	.00043	.00025	.0009	.0007	.0014	.0012	.0020
50	65	1.9685	2.5591	—	.00059	.00035	.0011	.0009	.0017	.0015	.0024
65	80	2.5591	3.1496	—	.00059	.0004	.0012	.0010	.0020	.0018	.0028
80	100	3.1496	3.9370	—	.00071	.00045	.0014	.0012	.0023	.0021	.0033
100	120	3.9370	4.7244	—	.00079	.0006	.0016	.0014	.0026	.0024	.0038
120	140	4.7244	5.5118	—	.00091	.0007	.0019	.0016	.0032	.0028	.0045
140	160	5.5118	6.2992	—	.00091	.0007	.0021	.0018	.0036	.0032	.0051
160	180	6.2992	7.0866	—	.00098	.0008	.0024	.0021	.0040	.0036	.0058
180	200	7.0866	7.8740	—	.00118	.0010	.0028	.0025	.0046	.0042	.0064