New advances in the techniques of electro‐chemical machining (ECM) have been achieved as a direct result of recent research at P.E.R.A. These advances include the development of novel machining systems for which patent applications have been made. The accuracy and production rates achieved using the P.E.R.A. Die‐sinking System are believed to be superior to those achieved using other known ECM techniques. The considerable progress already made has been due in part to the fact that the basic techniques evolved have been tested in the course of studies covering a very wide range of production problems and sponsored by member‐firms. In addition, theoretical studies have led to the development of methods of predicting machining conditions for particular applications.