Established in 1943, O. Keller Tool Engineering Company is one of the largest machine shops in the Midwest. The company offers design/build services for precision details, fixtures, gages, pallets and special machines. It has received an ISO 9002:1994 certification from the International Organization for Standardization. O. Keller Tool Engineering Company also builds a variety of gages, including hand held and table top gages and checking fixtures. The company maintains a variety of mills, lathes and grinders for precision machining applications. It provides project management services that include various lift assists and subassembly type tooling. O. Keller Tool Engineering Company additionally offers inspection, welding, fabrication, drilling, turning, sawing and grinding services.