Drahterodieren & Senkerodieren

Wire EDM

A brass or coated wire, typically 0.10 to 0.25 mm in diameter, is fed continuously through the workpiece while a dielectric flushes the gap. Because there is no mechanical contact, hardened 62 HRC tool steel cuts as readily as annealed material, and a 0.5-mm-thick part does not deflect.

We run four-axis machines with independent upper and lower guides, which allows tapered and transitioning profiles — a square on top blending into a circle at the bottom, for example.

Typical applications: extrusion dies, blanking punches and dies, keyways in hardened shafts, collets, tight-radius internal corners, and separating prototype parts from a plate without damaging them.

Sinker EDM

A shaped graphite or copper electrode is sunk into the workpiece to burn a cavity that mirrors its form. This is how blind pockets, deep ribs, sharp internal corners and complex three-dimensional mould detail get made in hardened steel.

Standard corner radius is 0.05 mm; smaller is possible with fine-finish electrodes. Surface finish ranges from Ra 3.2 µm on a roughing setting to Ra 0.2 µm on a mirror-finish cycle.

Accuracy and edge quality

Positional accuracy of ±0.005 mm is routine on wire work. The recast layer left by the spark is controlled by a finishing pass at reduced energy; where a drawing prohibits recast entirely, we follow with a light grind or etch and state that on the process plan.

Parts leave the wire burr-free by nature of the process, which removes a whole deburring operation from delicate components.

When to specify EDM on your drawing

Call out EDM when you need an internal corner radius smaller than 0.5 mm, when the material is already hardened, when the wall is too thin to withstand cutting force, or when you cannot accept the burr and edge roll that milling leaves behind.