Aoyama Seisakusho Co., Ltd.

Kenya Yamada

Satoshi Konagaya

Hiromichi Mizuno

Kazuhiro Koga

Sadayoshi Hasegawa

Mitsuru Kozawa

Satoshi Iida

There is provided a seizure prevention bolt capable of preventing seizure caused by oblique insertion as well as seizure caused by invasion of a foreign matter such as a spatter. An incomplete screw portion having an outer diameter d that is larger than an inner diameter Dof a female screw and smaller than (D+D)/2 is formed at a front end of a normal screw portion formed in a bolt shaft over one or more pitches, and a vertical groove for cutting out a foreign matter such as a spatter is formed in the incomplete screw portion. D in the above expression is a nominal diameter of the bolt.

Seizure prevention bolt

Provided is a nut into which a bolt () including a male-threaded portion with a male-threaded external diameter d and a male-threaded core diameter dis screwed, wherein a bolt insertion side end of a female-threaded portion () formed in a nut body () is provided with an incompletely threaded female portion () that is formed by one to three pitches so that an internal diameter dimension D is larger than (d+d)/2 and is smaller than the male-threaded external diameter d. Accordingly, even when the bolt is screwed into the nut in the inclination direction, the bolt may be rotated about a contact surface with respect to the incompletely threaded female portion (), and hence seizing may be prevented.

Anti-seizing nut

A tapping screw fastened to a subject member in which a thread portion formed in a shaft portion of the tapping screw is used to form a female screw thread in a prepared hole of the subject member. An angle of a thread ridge is approximately 30 degrees, a plurality of notches are formed in a top portion of the thread portion over a predetermined range of an entire length of the shaft portion, and a joint portion for connecting the top portion and a bottom portion of the thread portion is formed to have a circular arc shape in an area having a smaller diameter than a diameter of the prepared hole of the subject matter, as viewed in a cross section including a shaft center of the tapping screw.

Growing community of inventors

Niwa-gun, Japan

Kenya Yamada