To provide a link plate in which sufficient residual compressive stress is given to the periphery of a pin hole to form the inner circumferential surface of the pin hole into a smooth surface, and which thereby has improved fatigue strength and to prolong the service life of a metallic mold for pressing.
A method is disclosed for manufacturing the link plate 100 for a roller chain, the link plate 100 being provided with round pin holes 110 at the front and rear parts in the chain running direction, wherein before heat treatment, circular grooves 120 are embossed by applying the load on the peripheries of the pin holes 110 while a pilot pin 140 is inserted into each of the pin holes 110, and after performing the heat treatment, the circular grooves 120 are further embossed.
Nobuo Fujimoto
Masayuki Miyake
Atsuo Kawai