Wire electrical discharge machining (EDM) is widely used in the medical manufacturing, aerospace, and injection-mold industries to make parts that conventional milling, turning, and grinding processes cannot. Wire EDM often involves unattended production or hard-metal machining, and parts are usually small, complex, or fragile. High part tolerance and surface finish play in as well.

Wire EDM machines work by submerging conductive materials in a dielectric and placing them near a taut wire carrying an electric current. This creates a tiny electrical spark that precisely erodes away the material. Accuracy, usually between ±0.0001 in. to ±0.00005 in., and surface finish depend on the wire quality, dielectric and ambient temperatures, and the machine's rigidity, movement accuracy, and spark-control precision.

Traditional, 5-axis machines have XYUVZ control. XY axes relate to lower head movement in the XY direction and UV axes relate to upper head movement in the same XY direction. The Z axis involves moving the upper head up or down before XYUV movement starts.

Machine operators typically mount and clamp parts directly on machine worktables. This limits parts to 2D operation. For 3D operations, the operator unclamps the part, then turns and re-clamps it. Operators can also clamp parts to manual indexers mounted on worktables. These indexers, which are not controlled by the machine, let operators rotate and cut parts without unclamping them. Current machines work with optional, programmable indexers. These mount to worktables and connect with power and control cables plugged into a port on the machine. Such indexers can be programmed to turn an arbitrary fixed rotation speed to index a part to another angle before machining begins.