A-One Seimitsu, Inc. engages in the manufacture and sale of collet chucks products, special cutting tools and cams for automatic lathe. It operates through the following segments: Collet Chuck, Cutting Tools, and Cam Automatic Lathe. The Collet Chuck segment offers collet chuck for general industrial and special machineries. The Cutting Tools segment manufactures cutting and polishing tools. The Cam Automatic Lathe segment provides cams for use in small automatic lathe and specialized machines. The company was founded by Katsuhiko Umehara in May 1965 and is headquartered in Tokyo, Japan.