Internal clearance is the amount of space between the inner raceway, outer raceway and balls.

radial play

Radial Play: up and down movement

axial play

Axial Play: end play, right and left movement.

Bearing internal clearance in operation is an important factor that has a significant influence on other factors such as noise, vibration, heat and fatigue life. The radial play in the bearing before it is fitted can be called the initial radial play. Residual or operational radial play is what is left when the bearing has been fitted. There should be a slight residual radial play in the bearing to minimize ball skidding and reduce axial play(end play). Correct selection of the initial radial play can avoid faster bearing wear.

radial internal clearance of standard deep groove ball bearings

nominal bearing
inner diameter
d(mm)
clearance
C2C0 (CN)C3C4C5
exceedbelowmin.max.min.max.min.max.min.max.min.max.
10
(be limited to)
-0721382314292037
101809318112518332545
1824010520132520362548
2430111520132823413053
3040111620153328464064
4050111623183630514573
5065115828234338615560
658011510302551467165105
8010011812363058538475120

radial internal clearance of miniatureĀ bearings

clearance
mark
MC1MC2MC3MC4MC5MC6
clearancemax.min.max.min.max.min.max.min.max.min.max.min.
053851081313202028

bearing clearance selection

Maximum bearing life is with very slight preload. However, a slight increase in this theoretical preload can have a considerably detrimental effect on the bearing life. C0(CN) is usually used for standard deep groove ball bearings, and MC3 is used for miniature bearings.Radial play has nothing to do with precision grade.

operating conditionclearance
clearance fit for inner and outer ring.
low axial load
no axial load carrying requirement
select bearing with reduced radial clearance
lower vibration and noise
low speed
MC1, MC2, C2
lower frictional torque
standard axial load
average axial load carrying requirements
slight interference fit for inner ring
clearance fit for outer ring
average/low speed
MC3, MC4, C0(CN)
extremely low frictional torque
high axial load
high axial load carrying requirements
heavy interference fit to support high loads or shock loads
large temperature gradient from inner ring to outer ring
high degree of shaft deflection
MC5, MC6, C3, C4,C5