An EDM block is a specially prepared block of conductive material such as steel that serves as the workpiece for the EDM process. EDM stands for Electrical Discharge Machining. An EDM block, also referred to as an Eroding Block, typically doesn’t pertain directly to the field of steel production or steel processing but more so to the realm of spark erosion (electro-erosive machining). This method removes material through electrical discharges.