Service
Wire & Sinker EDM Services
Esco Precision offers both wire EDM and sinker (ram) EDM for cutting hardened tool steels, carbide, and exotic alloys to fine detail and sharp internal corners that conventional machining cannot reach.
Electrical discharge machining removes material with controlled electrical sparks rather than cutting force, so there is no tool pressure and no work hardening. That makes EDM ideal for hardened parts, thin walls, delicate features, and materials that are difficult or impossible to mill or turn. Because the process is essentially burr-free, it is well suited to critical edges and mating features.
Wire EDM uses a fine electrically charged wire — typically 0.004 to 0.012 in — to cut through-features with extremely accurate profiles, tight internal radii, and excellent edge quality. It excels at intricate contours, tapered walls, and stacked-part production. Sinker EDM burns a shaped electrode into the workpiece to produce blind cavities, sharp internal corners, keyways, and complex 3D detail — the go-to process for mold and die features.
We hold positional accuracy to approximately ±0.0001 in (±0.0025 mm) on wire work, with fine surface finishes achievable directly off the machine. Internal corner radii down to the wire radius let us produce near-square corners that end mills cannot cut. Parts are machined from your model or drawing and inspected against the print before release.
EDM is frequently combined with our milling and turning operations to complete tooling, dies, and precision components. All work runs under Esco’s ISO 9001:2015 quality system with documented inspection.
Common applications
- Stamping die and mold components
- Sharp internal corners and keyways
- Extrusion dies and profile tooling
- Fine slots, apertures, and gauges
- Hardened production tooling
- Complex prototypes in exotic alloys
Frequently asked questions
What tolerances can wire EDM hold?
Wire EDM routinely holds positional accuracy to about ±0.0001 in (±0.0025 mm) with excellent edge quality straight off the machine. Because there is no cutting force, thin and delicate features stay distortion-free.
What is the difference between wire EDM and sinker EDM?
Wire EDM cuts through-features with a fine traveling wire — ideal for profiles, contours, and tapers. Sinker (ram) EDM burns a shaped electrode into the part to create blind cavities, sharp internal corners, and 3D detail, which is why it is the standard for mold and die work.
Can EDM cut hardened steel and carbide?
Yes. EDM removes material with electrical sparks rather than a cutting edge, so it machines fully hardened tool steel, tungsten carbide, titanium, and superalloys without work hardening or tool wear from part hardness.
How sharp an internal corner can wire EDM produce?
Internal corner radius is limited by the wire radius — with a 0.004 in wire you can produce internal corners near 0.002 in radius, far sharper than any end mill can cut.
Is EDM a burr-free process?
Essentially, yes. EDM applies no mechanical cutting pressure, so parts come off the machine free of the burrs and edge roll that milling and turning can leave, which reduces or eliminates deburring on critical edges.
Related services
CNC Milling
3-, 4-, and 5-axis CNC milling of tight-tolerance metal and plastic parts, from prototypes to production volumes.
CNC Turning
CNC lathe turning with live tooling for round and prismatic parts — shafts, bushings, fittings, and pins to tight concentricity.
Metal Stamping
Precision stamping and forming of sheet-metal parts — blanking, piercing, coining, and bending from prototype to high volume.
Need wire & sinker edm for your next project?
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