EDM Sinker

CNC EDM Sinker Machining Services

JPT has the Sinker EDM Capacity to meet your production needs.

In conjunction with JPT’s extensive manufacturing services we also offer 4-axis CNC Sinking EDM as well. This capability allows us to better serve the needs of the toolmaker and component manufacturers.

Sinker EDM, also known as plunge EDM, RAM EDM or CONVENTIONAL EDM creates shapes in metal surfaces by spark erosion, using a shaped electrode formed as the reverse of the desired shape.

Our Sinker EDM has a programmable C-Axis for applications such as threads, helixes, and contour machining. Multiple component setups and multi-cavity components can be concurrently machined.

Sinker EDM can cut hard materials that would be difficult to cut using conventional machining, our large work tank allows us to machine parts 27 x 36″ and up to 1,100 lbs. .

The process can also cut difficult shapes such as sharp inside corners and deep small precision holes but shapes must not have undercuts, grooves, etc.

A few example of parts that can be manufactured using sinker EDM include injection mold tooling, micro hole drilling, punch and die tooling, scientific research apparatus, etc.

Sinker EDM can cut a variety of metals including very hard and exotic metals. Custom tooling in the reverse shape of the desired formation is needed for the process.

We can provide almost any style of electrode needed for your project including those that require 3-axis surface machining. If you choose, you can provide your own electrodes for your project as well.

We utilize 3R Macro tooling but can adapt to utilize other brands and styles of holders as well.

The full computer control allows machining or erosion in any direction; down, up, sideways, or at any 2-D or 3-D vector and will orbit in any real or imaginary plane.

Up to 25 electrodes can be loaded into the automatic electrode changer. When the program calls for the next electrode, an arm automatically changes the electrode and the program continues.

This allows for true lights-out, unmanned 2nd shift, 3rd shift, and weekend operation.

Think about this: there are 63 hours between 5:00 p.m. Friday and 8:00 a.m. Monday.Imagine what this can do to your delivery times.

Whether your project requires CNC Sinking EDM as one of many operations in the manufacturing of your complete component or you simply require EDM job shop services, we look forward to the opportunity to serve your need.


  • JPT Whitepapers


    Learn how cycle time reduction using the JPT Way can help increase profitability in this informative white paper.

  • The JPT Difference

    50+ Years Engineering Excellence – in Tooling & Component Manufacturing
    Backed by decades of experience, JPT delivers proven precision tooling solutions engineered for demanding machining applications.

    20+ Countries w/ Active Clients & Installations
    JPT supports manufacturers worldwide, delivering tooling solutions across global production environments.

    Millions of Components & Tools Delivered Annually
    From prototype to high-volume production, JPT tooling is built to perform consistently across large-scale manufacturing runs.

    ISO 9001:2015 Certified & Aerospace-Compliant Facility – Built for Quality, Certified to Perform
    Every process follows ISO 9001:2015 Certified standards, ensuring repeatable quality and precision across critical applications.

    Custom-Engineered Solutions
    Each tool is designed to meet exact specifications, solving complex machining challenges with precision and efficiency.

    Confidentiality & Supporting Solutions – Trusted by Tier 1 suppliers & OEMs
    JPT operates as a trusted partner behind the scenes, supporting Tier 1 suppliers and OEM production lines with proprietary solutions.

    Low-Volume Part Production – Ideal for prototyping, spares, and specialty defense projects
    Flexible production capabilities support everything from prototype development to specialized low-volume applications.

    Application-Specific Engineering & Tool Design – Engineered for your exact part geometry
    Every solution is engineered around your part geometry to optimize accuracy, cycle time, and performance.

    Advanced Tool Life Optimization – More uptime, fewer changeovers.
    Optimized tool design and materials extend tool life, reduce wear, and maximize uptime in production environments.

    Made in the USA – Built with pride, precision, and speed.
    Manufactured in the U.S., JPT tooling combines precision craftsmanship with fast, reliable delivery.

    Custom & Standard – Tailored solutions for your needs, ranging from custom indexable cutting tools to standard designs.
    From fully custom tooling to standard solutions, JPT offers a broad range of options to match your manufacturing needs.

    Fast Turnaround Times – Minimize downtime & maximize productivity.
    Streamlined engineering and manufacturing processes help reduce lead times and keep production moving.

    Have a new project or tooling challenge? Let’s talk. Our team is ready to help you find the most cost-effective solution for your specific application.

    The JPT Way

    Most tooling problems aren’t solved by buying off the shelf. They’re solved by understanding the application, the machine, and the process — then engineering the right solution.

    Cutting tools. Fixturing. Complete production solutions. That’s been the JPT way since 1971. No catalogs. No guessing. Just engineering.