Abstract: In order to provide a wheel nut wrench in which strength of a nut socket portion is allowed to be increased even though processes are facilitated under a situation where a tube made of carbon steel such as S45C is used as a material, and a manufacturing process thereof, an embodiment to implement the present invention is a wheel nut wrench made with a tube-shaped steel tube and provided with a nut socket portion at least one end, a nut socket shell portion whose inner and outer peripheries are both formed in a hexagonal shape is provided at an end portion of the steel tube, a sleeve made of a steel plate and having a cross section of a hexagonal shape is pressed into the nut socket shell portion, and a portion of the nut socket shell portion is deformed toward the sleeve to thereby achieve unification of the nut socket portion and the sleeve.

Abstract: In order to provide a manufacturing process for a wheel nut wrench in which strength of a nut socket portion is increased even though the process is facilitated under a situation where a tube made of carbon steel such as S45C is used as a material, the process includes the steps of: using a tube-shaped steel tube, forming a nut socket shell portion having a cross section of a hexagonal shape at an end portion thereof by cold pressing, pressing a sleeve made by a belt-shaped steel plate being bent and having a cross section of a hexagonal shape into the nut socket shell portion, and unifying a nut socket portion with the sleeve by plastic deforming.

Abstract: A hollow housing of a screw-type jack is integrally formed by a press. A ram is mounted in the center portion inside this housing in an axial direction to be extendable/contractible in a vertical direction. A drive mechanism mounted in the housing, for extending/contracting this ram in the vertical direction, and in which the housing includes a cylindrical shaft portion protrudingly disposed on a lower part of a side surface of the housing. A drive gear is pivotally and rotatably supported in the cylindrical shaft portion. The housing is made up of a plurality of housing pieces which are vertically divided portions of the housing. The housing pieces are mechanically joined to each other to form the housing. The housing pieces are divided in a vertical direction cutting though the axis of the cylindrical shaft portion. Joining of the housing pieces can use rivets or joining pieces can be swaged over protruding flanges.