The use of CAD (Computer Aided Design) to increase the productivity of engineers and to provide a digital product definition for Manufacturing's use with computer-controlled machinery is virtually accepted as the standard in the aerospace industry today (as well as many other kinds of industries). Increased aerospace customer emphasis on subcontracting and co-contracting activities requires that digital product definition data be exchanged between contractors who utilise differing CAD/CAM systems. Initial Graphics Exchange Standard (IGES) is a National Bureau of Standards' sponsored mechanism for exchange of such data. A review of this mechanism and its use to manufacture parts exchanged between differing systems will be described. Also discussed will be limitations of present data exchange mechanisms and current efforts and plans underway to provide a means of exchanging a more complete product description.