This part of ISO 12240 specifies dimension series, tolerances and radial internal clearances for radial spherical plain bearings. The dimensions and tolerances specified in this part of ISO 12240 have been selected to permit the design of radial spherical plain bearings using a wide choice of sliding material combinations. The specified tolerance values apply to finished, radial spherical plain bearings before any coating, plating, ring splitting or ring fracturing. In the case of surface treated radial spherical plain bearings, there may be slight deviations from the specified tolerance values. Radial spherical plain bearings need not conform to the designs illustrated but compliance is required as regards the dimensions, tolerances and radial internal clearances specified. NOTE - Spherical plain bearings for airframe applications are not covered by this part of ISO 12240.