Fluid dynamic bearing, method of manufacturing fluid dynamic bearing, rotating device, and disk drive device

A fluid dynamic bearing includes a shaft to which a resin flange is fixed by insert molding. The process where the flange is fixed to the shaft by insert molding includes a flange forming process in which the flange, fixed to the shaft, is formed by injecting the resin into a filled portion in the lower mold through an upper mold, while cooling at least part of the shaft, arranged in a shaft arrangement portion in a lower mold, with cooling water circulating through a cooling pipe.