Wire EDM
Also known as: WEDM, Wire Electrical Discharge Machining, Wire-Cut EDM
Wire EDM (Electrical Discharge Machining) uses a continuously fed thin wire electrode (typically 0.1–0.3 mm diameter brass or coated wire) to cut electrically conductive parts via controlled spark erosion. The wire never contacts the workpiece — material is removed by plasma discharges across a dielectric fluid gap (deionised water). Kerf width is 0.12–0.35 mm. Wire EDM achieves tolerances of ±0.005 mm and surface finishes of Ra 0.05–0.8 µm in finishing passes.
Why AM parts need this
Wire EDM is the standard method for separating LPBF and DED parts from their build plates. Bandsaw or angle-grinder cutting introduces vibration that can fracture thin walls and lattice structures in as-built (unsupported) AM parts. Wire EDM's non-contact spark removal produces a clean kerf with no mechanical force on the part. Wire EDM is also used to cut internal features into hardened AM tool steel inserts (e.g., MS1 at 50–54 HRC) after ageing — conventional milling struggles with these hardness levels.
Achievable surface finish
Achievable Ra
0.05–0.3 µm
Multi-pass finishing cuts. Single-pass separation cut: Ra 1–2 µm.
Key parameters
0.2 mm is standard for build-plate separation. 0.1 mm wire for tight-radius internal features.
Speed depends on material, thickness, and desired surface finish. Ti-6Al-4V: ~8–12 mm²/min at standard finish.
As-cut (single pass): Ra 1–2 µm. Finishing passes (3+): Ra 0.05–0.3 µm.
Must be accounted for in datum surfaces on AM preforms. Wire diameter + spark gap.
±0.005 mm achievable in precision machines (Fanuc, Sodick, AgieCharmilles). Standard: ±0.01–0.02 mm.
Compatible materials
Limitations
- Only works on electrically conductive materials — not applicable to polymer AM
- Minimum feature wall: ~0.3 mm to avoid thermal damage from spark heating
- Re-cast layer (0.002–0.02 mm) forms on EDM surfaces — must be removed by subsequent polishing for fatigue-critical parts
- Slow for thick sections — build plate separation of 30 mm Ti-6Al-4V: ~45–90 min per part
- Machine size limits large builds — standard WEDM travel: 300–600 mm × 250–500 mm
Related tools
Providers
Sodick — Wire EDM for AM Support Removal
Japanese precision machining OEM Sodick — wire EDM and die-sink EDM systems widely used in AM post-processing to cut support structures, separate LPBF parts from build plates, and achieve tight-tolerance features.
Yokohama, JP
GF Machining Solutions (AgieCharmilles)
Georg Fischer AG machining division — AgieCharmilles wire EDM and die-sink EDM alongside high-speed milling centres for AM post-processing, hybrid additive-subtractive workflows, and precision finishing of LPBF parts.
Geneva, CH
Relevant standards
Parameter ranges from Sodick and AgieCharmilles published technical specifications (manufacturer tier). Tolerance from GF Machining Solutions application notes.
All post-processing