The Dalzen Tool & Mfg. Co. was a manufacturer of threading tooling and threading machinery including thread grinders, ground thread taps, and broaches. There seems to be some connection to Snyder Tool & Engineering Co. and that remains a topic of future research.
In 1950, the company president, Fred Dalzen, reorganized the company with a merger between Dalzen Tool & Mfg. Co. with the St. Clair Machine Products and the Parker Plow Co. to form a new company, the Dalzen Tool Manufacturing Co. The former St. Clair Machine Products company was a defense plant that started during WWII to manufacture aircraft and automotive parts, and heating equipment but was shut down about two years after the end of the war. The new Dalzen Tool Manufacturing Co. manufacturerd broaches, cutting tools and general aircraft parts.
Information Sources