Sinker EDM Machining Services for Complex Internal Features

For Features That No Cutter Can Reach.

EDM (Electrical Discharge Machining) Services

Sinker EDM Machining Services for Complex Internal Features

For Features That No Cutter Can Reach.

EDM (Electrical Discharge Machining) Services

Wire EDM, Sinker EDM, And Small Hole EDM

Die Technology Inc provides ultra-precision wire EDM, sinker EDM, small hole EDM, and micro EDM services. With almost a million hours of EDM experience, we can handle the most challenging projects.

Precision Sinker EDM for High-Tolerance, Hard-to-Reach Geometries

Sinker EDM — also referred to as plunge EDM or conventional EDM — is a non-contact machining process used to create precise internal cavities and complex geometries, especially in hardened or exotic materials. By shaping a custom electrode to match the desired feature, the sinker EDM machine “sinks” it into the workpiece using controlled electrical discharges, allowing for extreme precision in blind pockets and sharp internal corners.

Die Technology is a trusted partner for CNC sinker EDM machining, with decades of experience producing ultra-precise tooling and components that meet the most stringent standards. Our team delivers exceptional results for OEMs in medical, aerospace, and advanced industrial applications — especially when geometry, material, and finish requirements go beyond what traditional machining can achieve.

What Is Sinker EDM?

Sinker EDM (also known as die sinking EDM) uses a shaped electrode — typically made of graphite or copper — and electrical discharges to remove material from the workpiece. Unlike wire EDM, which cuts through a part using a moving wire, sinker EDM creates internal shapes, blind pockets, and sharp corners that are otherwise impossible to reach with traditional tools.

Think of it like creating a mold cavity by “burning” its negative shape into hardened steel using a precise, controlled spark. The electrode never touches the material, so there’s no cutting force — ideal for injection mold features, micro machining, and high-hardness alloys.

This process is crucial in high-precision mold making, tool & die, and complex component manufacturing, especially when other methods can’t meet geometric or material challenges.

Sinker EDM vs. Wire EDM: Which Process Do You Need?

Both sinker EDM and wire EDM use controlled electrical discharges to machine hardened and exotic metals without mechanical force — but they solve different problems. Here’s how they compare:

Factor

Sinker EDM

Wire EDM

How it cuts

Shaped electrode “sinks” into the workpiece

Thin moving wire cuts through the part

Best for

Blind cavities, internal features, sharp inside corners

Through-features, profiles, punches & die openings

Typical uses

Mold cavities, die inserts, micro pockets

Progressive dies, form tooling, intricate profiles

Geometry

Internal / blind shapes

Cut-through shapes

Not sure which you need? Many parts use both — and Die Technology runs wire and sinker EDM under one roof, so we’ll recommend the right approach (or combination) for your part.

Die Technology’s Capabilities in Sinker EDM Machining

Precision That Sets Us Apart

At Die Technology, our sinker EDM services support the highest levels of precision, with:

  • Positional accuracy down to ±1 micron
  • Surface finishes to Ra 0.08 µm
  • Electrode-based machining for intricate internal shapes
  • Compatible with carbide, titanium, MP35N, Inconel, and hardened steels
  • Sharp internal corners and blind geometries unachievable with other methods

We utilize CNC sinker EDM machines optimized for accuracy and repeatability. Whether you’re working with micro parts, mold inserts, or hardened die components, we can help bring your most demanding designs to life.

End-to-End Solutions

Die Technology supports your project from concept to completion, including:

  • Sinker EDM electrode design and manufacturing in graphite, copper, and copper tungsten for unique geometries
  • Integration with wire EDM, grinding, and precision milling
  • Custom tooling solutions and complex die components
  • Collaboration with OEM engineers to meet tight deadlines and compliance standards

We also support high-mix, low-to-mid-volume production runs, making us a strong fit for aerospace and medical device manufacturers that need reliability, agility, and trusted results.

Features, Benefits, and Applications

Features

  • CNC sinker EDM for blind cavities and internal features
  • Ultra-fine surface finishes (Ra < 0.1 µm)
  • Precision feature machining down to ±1 micron
  • Electrode machining in graphite, copper, or copper tungsten
  • Carbide, hardened tool steel, titanium, and exotic alloy compatibility
  • Micro-cavity and sharp corner capability

Benefits

  • No part deformation or mechanical stress
  • Perfect for complex geometries and sharp internal features
  • High repeatability in difficult-to-machine materials
  • Combines with wire EDM for complete tool builds
  • Burr-free finishes and minimal post-processing
  • Ideal for prototypes, short runs, or production-scale builds

Applications

  • Blind pockets with square corners
  • Medical device tooling and fixtures
  • Injection mold electrodes and cavities
  • High-performance die inserts

Why Choose Die Technology for Sinker EDM Machining?

Die Technology brings over three decades of micron-level precision EDM experience to every sinker EDM project. We combine deep technical expertise, in-house tool design, and high-performance machinery to deliver the most demanding features in the toughest materials, and we do it for the love of precision. When your part demands accuracy, clean finishes, and internal geometries that no other method can achieve, we’re the partner you can trust.

Frequently Asked Questions

Who is your ideal customer?

We work with large OEMs in the medical, aerospace, electronic, energy, or defense industries in the U.S. who seek smart manufacturing solutions and value specialized manufacturing capabilities, equal partnerships, and micron-level precision. We target ideal-fit partners who share our values and have the potential to become strategic, long-term customers.

What’s the difference between sinker EDM and wire EDM?

Sinker EDM uses a shaped electrode to “sink” internal cavities and blind features, while wire EDM uses a moving wire to cut through-features and profiles. Tool manufacturing often requires both.

What materials are sinker EDM electrodes made from?

We machine sinker EDM electrodes from graphite, copper, and copper tungsten, selected to match your geometry and finish requirements.

How precise is your CNC sinker EDM?

Our CNC sinker EDM machines deliver micron-level precision with surface finishes down to Ra 0.08 µm.

Is sinker EDM also called die sinking EDM?

Yes. Sinker EDM, die sinking EDM, plunge EDM, and conventional EDM all refer to the same electrode-based process.

Ready to Get Started?

Let’s talk about your next sinker EDM project. Whether you’re producing hardened steel mold inserts, aerospace components, or ultra-precise internal tooling — our experts are ready to support you. At Die Technology, we do right by our partners and stand behind what we make, that’s our guarantee.

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Frequently Asked Questions

Sinker EDM uses a shaped electrode to “sink” internal cavities and blind features, while wire EDM uses a moving wire to cut through-features and profiles. Many tools use both, and we run both in-house.

We machine sinker EDM electrodes from graphite, copper, and copper tungsten, selected to match the material of the tool, and surface finish requirements.

Our CNC sinker EDM machines hold positional accuracy to ±1 micron.

Yes. Sinker EDM, die sinking EDM, plunge EDM, and conventional EDM all refer to the same electrode-based process.