In wire electrical discharge machining (WEDM), or wire-cut EDM, a thin single-strand metal wire, usually brass, is fed through the workpiece, typically occuring submerged in a tank of ELECTRIC fluid.

This process is used to cut plates as thick as 300mm and to make punches, tools and dies from hard metals that are too difficult to machine with other methods. The wire, which is constantly fed from a spool, is held between upper and lower diagonal guides.