Fw=needle roller enveloping circle in the tolerance zone F6.
2)The basic load ratings C and C0apply if the bearing outerring(with cylindrical outside surface) is mounted in a housing bore with the normal rolling bearing fit; when used as a track roller,the load ratings Cw and Cow apply.
3)Limiting speed for grease lubrication.with oil lubrication,the speed can be increased by approximately 30%.