Mayville Engineering Co., Inc. Gap fill Trade engages in the manufacture of metal components. It offers a broad range of prototyping and tooling, production fabrication, coating, assembly, and aftermarket components. Its customers operate in a diverse end markets, including heavy- and medium-duty commercial vehicle, construction, powersports, agriculture, military, and other end markets. The company was founded by Leo Bachhuber and Ted Bachhuber in 1945 and is headquartered in Mayville, WI.