Carl Weller founded Weller Electric in Easton, Pennsylvania in 1945 and invented the welding gun. He has been looking for solutions to serve the rapidly growing radio rework business market. With the invention of the welding gun, the first welding pen was released in 1950 and the temperature control function of the welding pen was first invented in 1976.
In 1959, Weller's business grew to Europe and was acquired by Cooper Industrial in the same year, which was listed on the New York Stock Exchange in 1970.

Throughout history, Weller continues to develop cutting-edge products for consumer goods and industrial markets. This tradition has continued to this day. Welleri has developed a professional series of welding pens. Weller's seven R&D teams invented multiple patents and won multiple awards, verifying Weller's commitment to technology. In 2007, the Weller University Training Center was built in Apex North Carolina and provides training to more than 100 trainees each year.