Klein Tools was founded in Chicago, Illinois, by German immigrant Mathias Klein in 1857. Klein developed and made a pair of side cutting pliers for a telegraph repairman. The company grew quickly as it began to make tools for telegraph, telephone, and electrical companies and their employees.
Today, Klein Tools continues to manufacture hand tools, specializing in electrical and telecommunications tools. The company manufactures nearly 4,000 different types of hand tools and tool bags. The company is still privately owned, with Thomas Klein as current CEO.
Klein Tool has its own drop forging plant in Moran, Kansas, as well as a distribution center in Cedar Rapids, Iowa. The company moved its headquarters in 2006 to Lincolnshire, Illinois.