Topura Co., Ltd.

Yousuke Okamura

Shigeto Mori

Mayumi Matsuno

Shunji Tozawa

A novel loosening prevention threaded fastener in which a clearance side protrusion portion protruding radially outwardly toward a clearance flank surface of a female screw thread is formed on a clearance flank surface of a male screw thread, and the clearance side protrusion portion is constructed such that a tip end portion thereof interferes with the clearance flank surface of the female screw thread, in a state where a pressure flank surface of the male screw thread is in contact with a clearance flank surface of the female screw thread. At the time of screw fastening, the crest end portion of the clearance side protrusion portion is pushed to the pressure flank surface of the female screw thread so that it is deformed in a deflective manner to apply a predetermined contact pressure to a contact surface due to its elastic restoring force, thus providing resistance against a loosening direction.

Loosening prevention threaded fastener

Provided are a coating agent capable of forming, on the periphery of a tapping screw, a coating layer which can hold female-thread-forming chips generated during screwing of the tapping screw into a prepared hole of a workpiece, thereby preventing scattering of the female-thread-forming chips; and a tapping screw having thereon a coating layer formed from the coating agent. The coating agent is a composition containing, as primary components, calcium montanate or a calcium-montanate-containing montanic acid species mixture, a thermoplastic resin emulsion, and water. The coating agent can form, on the periphery of a tapping screw, a coating layer which exhibits a lubricating function, and a function of capturing female-thread-forming chips.

Coating agent for tapping screw, method for preparing the coating agent, method for forming coating layer on the periphery of tapping screw using the coating agent, and tapping screw having coating layer formed from the coating agent

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Hadano, Japan

Yousuke Okamura