by Kat Griffin Kat Griffin

Exploring EDM Water Treatment Systems

In Electrical Discharge Machining (EDM), where thorough flushing is crucial, ensuring the chemical purity of dielectric water is of utmost importance. This exploration delves into the prevalent systems used to uphold the integrity of the dielectric water vital for both Wire and Small Hole EDM processes. Learn the various types of systems used in EDM to maintain the quality of dielectric fluid.


  • Refillable Bottle Systems: In the early stages of Wire EDM, machines often included resin containers tended to by operators. This arduous process involved replacing depleted resin, cleaning containers, and refilling them with loose resin. However, the mess and hassle associated with this method rendered it unpopular. Moreover, disposing of contaminated resin posed environmental concerns.
  • Dual Bed Systems: This setup, comprising separate tanks for anion and cation resin connected in series, was once efficient but gradually fell out of favor due to the inconvenience of managing separate tanks.
  • Mixed Bed Systems: Combining anion and cation resin in a single container, mixed bed systems now dominate EDM water treatment due to their efficacy.
  • Bag Type Mixed Bed Systems: Enclosed cloth bags filled with mixed bed resin offer a convenient solution. When it’s time for resin renewal, the exhausted bag is simply replaced with a new one.
  • Tank Type Mixed Bed Systems: Most contemporary machines utilize fiberglass tanks containing mixed bed ion exchange resin. Once exhausted, these tanks are either regenerated or exchanged for fresh ones.resin tanks
  • Filtration Systems: These systems employ filters to remove contaminants, particles, and debris from the dielectric fluid, ensuring its purity.
  • Ion Exchange Systems: Ion exchange systems use ion exchange resins to remove dissolved ions and impurities from the dielectric fluid, improving its conductivity and overall quality.
  • Reverse Osmosis (RO) Systems: RO systems utilize semipermeable membranes to remove dissolved salts, minerals, and other impurities from the water, producing high-purity water for EDM applications.
  • UV Sterilization Systems: UV sterilization systems use ultraviolet light to disinfect and sterilize the dielectric fluid, eliminating bacteria, algae, and other microorganisms that can degrade its quality.
  • Distillation Systems: Distillation systems heat the dielectric fluid to its boiling point, then collect and condense the vapor to produce purified water, effectively removing contaminants and impurities.
  • Electrodeionization (EDI) Systems: EDI systems combine ion exchange resins with an electric current to continuously remove ions and impurities from the dielectric fluid, producing high-purity water without the need for chemical regeneration.

Resin System Accessories

Two essential accessories enhance the functionality of resin systems:

  • Resin Strainer: Prevents resin beads from contaminating the water system by filtering outlet flow.
  • Conductivity Light: Monitors water conductivity post-deionization, signaling the need for resin replacement before conductivity reaches alarming levels.


In summary, the deionizing system is essential for reliable EDM operation. Removing impurities from the water, ensuring optimal conductivity. Additionally, it safeguards against electrode corrosion, prolonging equipment lifespan. Furthermore, it enhances machining precision, leading to quality machining. Overall, its significance cannot be overstated and maintaining these systems are vital for sustained productivity.

Special thanks to Roger Kern from EDM Today for inspiring this blog post.

by Kat Griffin Kat Griffin

Exploring Dielectric Fluid in Sinker EDM: An Overview of its Purpose and Functions

Sinker EDM machining is used to produce high-precision parts from a variety of conductive materials, which require an electrode, typically made of graphite or copper. The electrode is then plunged toward the raw material/workpiece that has been submerged in a dielectric fluid. Dielectric fluid, often underestimated in its significance, plays a crucial role in enhancing the efficiency, precision, and overall performance of Sinker EDM. In this blog post, we will explore the purpose and functions of dielectric fluid in Sinker EDM, shedding light on its role in the machining process.

The Role of Dielectric Fluid in Sinker EDM

Oil-based dielectric fluid serves multiple functions in the Sinker EDM process, contributing significantly to its success. Here’s a breakdown of its primary roles:

  • Cooling and Thermal Management: Dielectric fluid acts as a coolant during the EDM process. As electrical discharges generate intense heat, the dielectric fluid absorbs and dissipates this heat, preventing the workpiece and the electrode from overheating. Efficient thermal management ensures the stability of the machining environment and prevents thermal-induced deformities in the workpiece.
  • Flushing Away Debris: The dielectric fluid serves as a medium to flush away the debris and eroded particles from the machining zone. This continuous flushing prevents the accumulation of debris, maintaining a clean and efficient working environment. It also helps in preventing the formation of a recast layer on the workpiece.
  • Electrical Insulation: Dielectric fluids act as electrical insulators, isolating the workpiece from the electrode. This insulation prevents premature arcing and short circuits, ensuring a controlled and stable EDM process. The dielectric fluid’s electrical properties play a crucial role in maintaining the spark gap and controlling the discharge.
  • Enhancing Machining Precision: The dielectric fluid’s ability to dissipate heat, flush away debris, and provide electrical insulation collectively contributes to improved machining precision. Consistent and controlled conditions facilitated by the dielectric fluid result in higher accuracy in reproducing intricate details on the workpiece.

sinker edm diagram

Tank Configuration

Sinker EDM machines typically have a tank filled with dielectric fluid where the workpiece and the electrode are being submerged. The fluid allows the electrical discharge to occur between the electrode and the workpiece.



While the fundamental role of dielectric fluid is to facilitate electrical discharge and remove debris in both sinker EDM and wire EDM, the specific requirements and applications may vary based on the machining process and machine configuration. The choice of dielectric fluid will depend on factors such as the material being machined, machine specifications, and desired surface finish.

Understanding the importance of dielectric fluid allows manufacturers to optimize their EDM processes, leading to higher efficiency and superior machining results. To learn about Dielectric Fluid in Wire EDM, click here.

by Kat Griffin Kat Griffin

Exploring Dielectric Fluid in Wire EDM: An Overview of its Purpose and Functions

dielectric fluid in wire EDM

Wire Electrical Discharge Machining (EDM) is a precision machining process that uses electrical discharges to shape or cut conductive materials. In the wire EDM process, a thin, electrically conductive wire cuts through the workpiece, and dielectric fluid serves as a medium to facilitate the cutting operation.

Historically, deionized water has been the choice for dielectric fluid in wire EDM, whereas oil is commonly utilized in sinker machines. Deionized water plays a crucial role in wire EDM by serving multiple purposes:

  • Electrical Insulation: The deionized water acts as an electrical insulator between the wire electrode and the workpiece. It prevents the electrical discharges from occurring prematurely and ensures that the electrical energy concentrates at the desired cutting point.

  • Temperature Control: During the wire EDM process, intense heat is generated at the cutting zone due to the electrical discharges. The deionized water cools the cutting zone, preventing excessive heat buildup and maintaining stable machining conditions.

  • Flushing Agent: Deionized water also serves as a flushing medium. It carries away the debris, metal particles, and erosion products produced during the machining process. This continuous flushing helps maintain a clean cutting area and improves the machining accuracy.



To optimize wire machine performance, users must maintain the cleanliness of their dielectric fluid at all times. If the fluid becomes excessively dirty, it can lead to rusting of materials inside the tank. This can result in compromised surface finish. Implementing effective maintenance practices involves regularly sending the resin for regeneration and periodically replacing the paper-filter cartridges in the system.



Regeneration is a process that takes ion exchange resin beads that are exhausted (fully loaded), and removes ions that have been picked up during the in-service cycle so the resin can continue to be used. An ion exchange system consists of a bed of resin beads with the ability to pick up hardness or other elements by ion exchange.


DI Regeneration Program

Simply purchase a regeneration coupon from us. Place the coupon with the spent bag, bottle or tank, then mail them to one of the four exchange facilities that represent your state. There the resin will be regenerated and returned to you. As the resin is worn out, it is topped off by virgin resin during the regeneration process.


Overall, the properties of deionized water make it ideal for wire EDM cutting, providing effective flushing, controlled sparking, temperature management, and cleanliness of the deionized water for optimal machining results.