Wire EDM

Wire EDM (wire electrical discharge machining) uses a thin, continuously travelling wire electrode to erode a path through an electrically conductive workpiece with a series of controlled sparks, guided along a programmed profile rather than plunged into a cavity.¹ It is the branch of EDM used for open, through-cut profiles rather than closed pockets, since the wire has to enter and exit the material along its cutting path.

What actually drives wire EDM cycle time

Cycle time depends on material thickness, required accuracy and surface finish, and the number of trim passes needed to reach a tight tolerance or a fine finish, not primarily on hardness.

Where it appears on the drawing

Implied by a through profile in a hardened or hard-to-machine conductive material, often with a tight positional or profile tolerance that a rough cut alone will not meet.

Common mistakes

Assuming wire EDM is a single pass. A tight tolerance or fine finish usually forces one or more trim passes after the rough cut, and skipping that step in an estimate understates both time and cost.

How is wire EDM different from sinker EDM?

Wire EDM cuts a through profile with a continuously moving wire; sinker EDM shapes a cavity by plunging a formed electrode into the material.

Does wire EDM work on any hard material?

Only on electrically conductive ones; a hardened but non-conductive material cannot be wire EDM'd.

Why does wire EDM sometimes need more than one pass?

A single rough cut is fast but leaves a rougher finish and looser tolerance; trim passes remove a thin layer to tighten both.