Founded in Dayton on January 27, 1942, Northwestern Tools makes American-made machine-tooling and work-holding components, including its own RE-NU thread-repair inserts. Still owned and actively managed by the Thomeczek family, the company has grown from four products to more than 2,000 domestic components and moved into a larger Dayton facility in 2018. Northwestern serves markets ranging from aerospace to medical manufacturing, with a third of its employees having more than 20 years with the company.