Sinker EDM Services

Prototype to Low Volume Production Sinker EDM Parts

F&M Tool and Die has 4 wire EDM and 2 EDM sinker machines ready to manufacture your prototype to low-volume custom manufactured EDM parts. We quote jobs in under 48 hours and deliver parts in 2-5 weeks, expedites welcome. Our sweet spot for EDM parts is in the 1-250 quantity range. Common EDM material used include Bronze, Copper, Tungsten, Carbon Steel, Stainless Steel, and more!

If you need intricate custom parts made from hard materials we are here for you!


  • Lead Time – Parts in 2-5 Weeks
  • Quoting – Quotes Returned Within 48 Hours
  • Volume – Quantities 1-250+
  • Part Size – Ranging from 1 in. x 1 in. x 1 in. to 35 in. x 26 in. x 15.5 in.  

What is Sinker EDM?

Sinker Electrical Discharge Machining (Sinker EDM), also known as die sink EDM or cavity-type EDM, is a non-traditional machining process used for the precision machining of conductive materials. Sinker EDM is particularly well-suited for producing complex shapes, cavities, and molds with high accuracy. This process is commonly employed in tool and die making, mold manufacturing, and aerospace industries.

Here’s a basic overview of how Sinker EDM works:

  1. Setup:
    • A conductive workpiece, typically made of materials like tool steel or carbide, is set up in the machine.
    • A specially shaped electrode, often made of copper or graphite, is also set up in the machine.
  2. Dielectric Fluid:
    • The workpiece and the electrode are submerged in a dielectric fluid (usually oil or deionized water). The dielectric fluid serves as both an electrical insulator and a coolant.
  3. Electrical Discharge:
    • A voltage difference is applied between the electrode and the workpiece. When the voltage reaches a critical point, an electrical discharge (spark) occurs between the electrode and the workpiece.
  4. Material Removal:
    • The spark generates intense heat, melting and vaporizing a small amount of material from the workpiece. This material removal process helps shape the workpiece according to the geometry of the electrode.
  5. Controlled Movements:
    • The electrode is controlled by CNC (Computer Numerical Control) to follow the programmed toolpath precisely. The movements are based on the desired shape of the final part.
  6. Finishing and Accuracy:
    • Sinker EDM is capable of achieving high accuracy and intricate details in the machined surfaces. The process allows for fine finishing, reducing the need for additional finishing steps.

Key advantages of Sinker EDM include:

  • Precision Machining: Sinker EDM is known for its ability to produce highly precise and intricate shapes with tight tolerances.
  • Complex Geometries: It is well-suited for machining complex and detailed cavities, molds, and dies.
  • Hard Materials: Sinker EDM can efficiently machine hard materials that are challenging for conventional machining methods.
  • Minimal Tool Wear: Since the electrode doesn’t physically contact the workpiece, there is minimal tool wear, resulting in consistent machining accuracy.

While Sinker EDM has its advantages, the choice between Sinker EDM and other machining methods depends on factors such as material properties, part geometry, and production requirements.

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