Double row cylindrical roller bearings produced to SP tolerance class specifications have C1 radial internal clearance as standard although the clearance suffix is not shown in the bearing designation. The rings of similar bearings may not be mixed as otherwise the clearance may become inadmissibly large or small. For this reason, the components of a bearing are supplied as a packaged unit. If they are separately packed, the components of one bearing will carry the same serial number.
Bearings made to SP tolerance class specifications, particularly those of series NNU 49, can also be supplied with larger radial internal clearance. If bearings with greater radial internal clearance than C1 are required the bearing designation should include the clearance class identification: C2 for the special "SPC2" clearance, CN for class Normal or C3, when ordering. The radial internal clearance "SPC2" differs from the standardized C2 clearance; the range is narrower and displaced towards the smaller end of the C2 range.
The other standard bearings are produced with the radial internal clearance as stated. The radial internal clearance of the drawing number bearings is given in the product table together with the design following the bearing designation.