SKF Seat washer for thrust ball bearing Series: U

To accommodate initial misalignment between the shaft and housing, both single and double direction thrust ball bearings are available with sphered seat surfaces on the housing washers. They can be used together with a sphered seat washer adjacent to the housing washer or adjacent to a machine component manufactured with a sphered surface.
Appropiate sphered seat washers must be ordered separately. Depending on the bearing series they have the basic designation U2, U3 or U4 followed by a two-digit number, which identifies the size e.g. sphered seat washer U 320 for bearing 53320.