Remarks: The minimum permissible chamfer dimensions rN on the snap-ring-groove side of the outer rings are as follows: Dimension series 18 : For outside diameters of 78mm and less, use 0.3mm chamfer. For all others exceeding 78mm, use 0.5mm chamfer. Dimension series 19 : For outside diameters of 24mm and less, use 0.2mm chamfer. For 47mm and less, use 0.3mm chamfer. For all others exceeding 47mm, use 0.5mm chamfer.