The wheel nut is a special nut used to fix the outer wheel hub of the automobile. Because of the uncertainty of the automobile nut, there is no national standard for the automobile nut, but the general type is roughly the same as the ordinary hexagonal nut, and there are also various types in the middle of M12-M42. Compared with ordinary hexagon nuts, hub nuts are generally thicker than hexagonal national standard nuts of the same specification, and generally have fine pitches. The thread pitch is also roughly 1.5 mm and 2.0 mm. The shape is the same as that of hexagon nuts. Equilateral hexagon, but there will be a taper at one end of the nut, some of the taper will have a step inside to place the nylon washer for locking, and some sides have no step! And some hub nuts have a flange on the tapered part, and generally there is a flange on the outside, there will be a step inside to place the nylon washer, and the general hexagonal nut is tapered.