To provide a bearing capable of preventing degradation of cylindrical degree when the bearing is completed by a mechanical fixing means in assembling a thrust bearing, solving problems such as leakage of lubricating oil and degradation of the bearing rigidity, and ensuring the consistent bearing rigidity, highly reliable and excellent in the durability in rotation for a long time.

A thrust bearing is formed by the mechanical fixing means on an end of a radial bearing member comprising integrated members, and manufactured to the predetermined dimensions considering the deformation of a radial bearing member in the mechanical fixing means when manufacturing the radial bearing. The mechanical fixing means employs the press-fit fixing or the caulk-fixing. An end on the thrust bearing side at the outline of the radial bearing member is reduced in size. The means may be stepped or tapered. The radial bearing is embodied by a dynamic pressure fluid bearing having a groove of herringbone shape.