Gold Screw

Leads in market share thanks to a fusion of artisan techniques and cutting-edge machining Our company is a jewelry parts & foged ring jewelry manufacturer based in Yamanashi Prefecture, a region which boasts the highest production volume of jewelry in Japan. We hold 50% of the domestic jewelry parts market, with a notable 70% in earring clasps. In the jewelry area, our specialization in forged rings, often used in bridal-related areas, has led us to create products in keeping with our customers expectations. It is no exaggeration to say that jewelry and other ornaments have a very long history, their origins coinciding with the birth of mankind. Since ancient times, craftsmen all over the world have relied on their own hands and tools alone in creating jewelry pieces; however, we are capable of pursuing both quality and quantity simultaneously by applying cutting-edge machining to the refined techniques of our craftsmen. Kohsai produces approximately 10 million pieces of jewelry parts annually and about 30,000 pieces of fogged jewelry (as of 2019). Despite the traditional difficulty of manufacturing jewelry, we are able to provide a stable supply of both these and jewelry parts with some of the best productivity and technological capabilities in Japan.