Original oil and gas trade magazine vintage ad for CHAIN BELT COMPANY of Milwaukee, WI. Rex offset side-bar roller chain for tough, rotary table drives. Designed for deep, high speed oilfield drilling. Oil field pumps you can depend on to prime when you need it. This chain is made up not cut up. Baldwin-Duckworth Division, Springfield, MA. This unique 1950 old two sided petroleum drilling equipment magazine advertisement would display beautifully matted and framed.