A cutting tool needs somewhere to go. A spark does not.
Sinker EDM to ±0.01 mm, wire EDM to ±0.002 mm, deep-hole EDM to 800 mm — in-house, on machines we designed and built. For internal cavities, curved flow channels and cross-holes no cutter can reach.
Some geometry has no milling solution. EDM is how it gets made:
Metal is removed by controlled spark erosion, so there is no tool pressure to deflect a slender shaft or close in a thin wall
The electrode never has to be harder than the work. Hardened tool steel, Inconel 718, non-magnetic stainless and titanium erode the same way
Internal cavities, curved flow channels, cross-holes and sharp internal corners are all reachable, because the electrode is not a spinning tool
A milling cutter always leaves its own radius behind; EDM leaves the corner that is on the drawing
EDM is measured in hours per feature and leaves a thin recast layer. Where a cutter can do the job, we use the cutter. EDM is for what the cutter cannot do
That is why we treat it as the process of last resort — not the cheapest or the fastest, but for some geometry the only one that works.
Four EDM processes, four different jobs:
| EDM process | Tolerance & finish | What it is for |
|---|---|---|
| Sinker EDM (die-sinking) | ±0.01 mm · Ra 0.8 μm | Internal cavities, deep slots and sharp internal corners in hardened material |
| Wire EDM — fine | ±0.002 mm · Ra 0.4 μm | Precision profiles, punches and dies, parting already-hardened parts |
| Wire EDM — fast | ±0.01 mm · Ra 3.2 μm | Roughing and non-critical profiles |
| Deep-hole EDM | Ø ±0.01 mm · Ra 0.8 μm | Complex cavities and internal features to 800 mm deep — on a machine we designed and built |
Sinker EDM. Six CNC-800 mirror-finish sinker EDMs on our own floor — the machines behind our mould and die work.
Ram-type mirror EDM. For larger mould and die work, a ram-type mirror-finish machine runs at our joint venture.
Wire EDM. Fine and fast wire machines, held to ±0.002 mm and ±0.01 mm respectively.
Deep-hole EDM — our own design. Two models, FWDHH-M4080 and FWDHH-L4070: three-axis CNC machines on an integrated gantry frame, three axes simultaneous, tuned for the same difficult alloys our other lines run — Inconel 718, non-magnetic stainless and titanium. They run at our joint venture.
The step that started it. On a hydraulic control unit body — three groups of high-precision deep bores inside one part — the deep-hole EDM operation used to be sent overseas, and the route ran about five months. We built our own deep-hole EDM, working through dielectric sealing and Z-axis accuracy, and brought the operation back in-house. The cycle came down by roughly a third.
| Application | Why EDM | Our record |
|---|---|---|
| Hydraulic control unit bodies | Three groups of high-precision deep bores inside one part | Deep-hole EDM brought onto machines of our own design — cycle cut by about a third |
| Downhole tool housings | Internal cavities and cross-holes no cutter can reach | In production for rotary-steerable and MWD/LWD programs |
| Moulds & dies | Sharp internal corners, mirror finishes, hardened steel | The company began as a tooling & mould shop in 1993 — this is where we come from |
| Hardened & exotic parts | Hardness-independent removal, no tool wear | Inconel 718, non-magnetic stainless, titanium — in batch production |
Reach geometry a rotating cutter physically cannot — internal cavities, curved flow channels, cross-holes and sharp internal corners — and do it in material that is already hardened. No cutting force also means no deflection on slender or thin-walled parts.
A single deep feature can run one to two weeks. EDM is not a shortcut — where a cutter can do the job, we use the cutter, and we quote EDM only where it is the right process.
Yes — hardness is irrelevant to the process. We run EDM in production on hardened tool steel, Inconel 718, non-magnetic stainless and titanium.
Both. Fine wire to ±0.002 mm with Ra 0.4 μm; fast wire to ±0.01 mm; sinker EDM to ±0.01 mm with Ra 0.8 μm.
Yes — full service from our material, or your supplied parts
Upload your drawing with the features a cutter cannot reach — an internal cavity, a curved channel, a cross-hole. Within 24 hours, an engineer responds with process feedback.
Related: Capabilities Hub｜Deep-Hole Drilling｜Special Processes｜Custom Machine Tools
