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Aerospace & Defense CNC Machining 21 Nov 2025

Wire EDM

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How Wire EDM Cutting Works

01 Setting Up the Machine

A thin, brass wire is fed from a spool, threaded through a series of guides to control its path, and is held under tension as it travels through the workpiece. A powerful electrical voltage is applied to the wire, which carries one charge, while the workpiece is connected to the opposite charge. Wire EDM cutting can only be done with electrically conductive metals.

WireEDM_Setting Up the Machine
02 Cutting the Metal

As the wire is brought close to the workpiece, sparks jump the gap, creating intense heat that melts and vaporizes a tiny amount of material from the workpiece. This results in a very precise cut. A dielectric liquid, such as deionized water, cools the metal and flushes away melted metal particles. That also helps to minimize heat-affected areas.

wireEDM
03 Finishing Passes

For the highest accuracy, the machine may perform multiple “skim cuts” using a slower speed and lower power to achieve a finer surface finish. Metal can be rough cut using wire EDM to a tolerance of .002 in. With trim passes, tolerance can be increased to .0002 in.

Finishing Passes_WireEDM

What Are the Pros & Cons of Wire EDM Cutting?

Advantages

  • Precision & Accuracy

    Wire EDM machining makes precise and accurate cuts, often within ±0.0002 inches, and cut intricate details with high accuracy.

  • Tight Corners

    Wire EDM cutting can create extremely tight corner radii, which is difficult with conventional machining methods. This capability is ideal for fabricating injection mold tools.

  • Ideal for Cutting Tough Materials

    Wire EDM can cut extremely hard, strong, and difficult-to-machine conductive materials that are challenging for traditional machining, such as Inconel, titanium and superalloys.

  • Efficient for Cutting Brittle Metals

    The lack of mechanical contact between the wire and the workpiece means delicate or weak parts can be machined without distortion.

  • Cost Effective

    Wire EDM cutting is surprisingly efficient: Metal plates can be stacked to cut multiple workpieces in a single pass.

Disadvantages

  • Conductivity Requirement

    Wire EDM can only machine electrically conductive materials, such as metals. It cannot cut non-conductive materials like most plastics, ceramics, or composites.

  • Slow Cutting Speed

    Wire EDM cutting is significantly slower than conventional machining, water jet cutting, or laser cutting, making it less efficient for simple or high-volume jobs.

  • Heat-Affected Edges

    A thin layer of oxide or recast material can form along the cut edge, which may need to be removed with a secondary process like electropolishing

  • Skilled Operator Required

    Wire EDM requires significant operator expertise to set up and run correctly.

Applications of Wire EDM Cutting

Wire EDM is equally well-suited to prototype and high-production parts, and industries like:

  • Automotive
  • Medical
  • Aerospace
  • Injection molding tools

Case Studies Block

What Materials Can Be Processed Using Wire EDM Machining?

Wire EDM cutting can only be used with electrically conductive metals, including these:

  • Copper
  • Carbide
  • Tungsten
  • Bronze
  • Carbon steel
  • Inconel
  • Stainless steel
  • Hastelloy
  • Kovar
  • Titanium
  • Carbon graphite
  • High alloy steel

Additional EDM Services Offered by Fathom

Sinker EDM

This type of EDM – also referred to as plunge EDM and die sinking – is designed to create blind pockets, where a hole doesn’t go all the way through the material. The electrode is formed in the desired shape of the cavity to be created in the metal. The electrode is slowly lowered (or sunk) into the workpiece, eroding material until the cavity is created. Sinker EDM is used to create complex shapes, such as those needed for making molds, dies and other types of tooling.

Learn more

Hole Popper EDM

A rotating tubular-shaped electrode is used to cut deep, small-diameter holes through the entire thickness of a conductive metal. It functions like a drill bit, except that an electrical spark is used to quickly and accurately cut these holes in the workpiece. This type of machine is sometimes used to create a starter hole for wire EDM to use to begin a cut.

Why Choose Fathom for Wire EDM Cutting?

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