Die-sinking EDM machines for industrial manufacturing
How a die-sinking EDM machine works
The die-sinking EDM machine is a machine tool for high-precision machining of electrically conductive materials by means of electroerosive removal. In contrast to wire EDM, die-sinking EDM does not use a wire, but a fixed electrode, usually made of copper or graphite, to "burn" three-dimensional contours into the workpiece. The method is particularly suitable for complex internal geometries, undercuts, or cavities that are difficult to produce using cutting processes.
The machining process is based on controlled electrical discharges. An electrical voltage is built up between the workpiece and the electrode. In a dielectric medium—usually oil—a large number of spark erosions occur when the distance between the two is small. These generate very high temperatures locally, causing the material on the workpiece to melt or vaporize at specific points. Material removal takes place without mechanical contact, which means that even hard or hardened materials can be machined.
The electrode is moved into the workpiece using CNC control. The electrode is lowered step by step, hence the name "sink erosion." Oscillating movements and automatic flushing processes continuously clean and cool the dielectric. The shape of the electrode determines exactly the shape that is transferred to the workpiece – with maximum dimensional accuracy and minimal burr.
Typical areas of application are tool and mold making, for example for the production of injection molds, die casting tools, or fine engravings. Die-sinking EDM machines offer maximum precision with low thermal stress on the workpiece and enable the production of even the smallest contours in complex components.
Die-sinking EDM machine
Structure of a die-sinking EDM machine
(Die-sinking EDM machine structure)
A die-sinking EDM machine consists of a machine bed with a CNC-controlled axis system (usually X, Y, Z), a work tank with dielectric fluid, a spindle unit for electrode guidance, and a clamping device for the workpiece. The control unit regulates the eroding process and the feed movements of the electrode. In addition, there is a dielectric system with a filter system, pumps, and temperature control. An automatic electrode changer unit can be integrated into modern machines. Sensors monitor voltage, current, and gap conditions for reliable machining.
Applications in industrial manufacturing
Die-sinking EDM machines are widely used in industry, particularly in tool and mold making, aerospace, medical technology, automotive engineering, precision engineering, and the watch industry. This process demonstrates its strengths wherever complex shapes and high precision are required.
Typical workpieces are:
- Injection molds
- Die casting tools
- Stamps and dies
- Die molds
- Inserts with undercuts
- Electrode molds
- Cooling channels in tools
- Engravings
- Mold inserts for plastic parts
- Filigree cavities for precision parts
Die sinking EDM is particularly suitable for hardened steels, carbides, and materials that are difficult to machine. It enables the production of complex 3D geometries that would be impossible or very difficult to achieve using conventional methods.
Wire and die-sinking EDM machines
There are two main types of erosion machines: the die-sinking EDM machine and the Wire EDM machine. In die-sinking, the electrode is shaped three-dimensionally and lowered into the workpiece. Wire EDM, on the other hand, uses a thin wire as the electrode, which is continuously guided through the workpiece – ideal for filigree contours and breakthroughs.
Tools for a die-sinking EDM machine
The central tool in a die-sinking EDM machine is the electrode, usually made of copper, graphite, or copper-tungsten. The electrode is manufactured individually according to the desired shape and then "burned" into the workpiece. Other tools and components include:
- Electrode holders
- Clamping systems
- Electrode changer
- Flushing nozzles
- Cooling and filter systems
- Electrode processing machines
- Cleaning brushes
- Adjustment mirrors
- Alignment systems
- Wear monitoring sensors
The quality of the electrodes, their dimensional accuracy, and the material used have a decisive influence on the machining quality and wear.
Voltage range of a die-sinking EDM machine
When operating a die-sinking EDM machine (die-sinking or sinker EDM), the voltages to be applied in the discharge gap vary considerably depending on the machine type, generator technology, workpiece material, and condition ("gap").
Typical voltage ranges:
1. Rough material removal (rough erosion/pre-finishing)
- Voltage: approx. 150–300 volts
- Current: high
- Pulse duration: long
- Objective: rapid removal of large amounts of material, rough surface
- Application: Pre-machining of cavities or large contours
2. Medium machining (finishing)
- Voltage: approx. 100–180 volts
- Current: medium
- Pulse duration: medium
- Objective: balanced ratio between material removal and surface quality
3. Fine finishing (fine erosion/finish machining)
- Voltage: approx. 80–120 volts
- Current intensity: low
- Pulse duration: short
- Objective: very smooth surfaces with low tolerances
- Application: final machining steps for mold inserts or precision parts
These values can be finely adjusted depending on the control system and generator technology. Modern machines automatically adjust the voltage and current to optimize spark stability and machining quality.
Accessories and operating materials for a die-sinking EDM machine
The most important thing is the dielectric, usually a special eroding oil, which is responsible for spark erosion as well as cooling and flushing. Filter inserts, pumps, and cleaning agents are also needed to keep the dielectric clean. Accessories include electrode blanks, electrode holders, workpiece clamping systems, measuring devices, automation modules (e.g., changers), and cooling units. CAM software for electrode design as well as adjustment and alignment tools support precise setup.
Leading manufacturers of die-sinking EDM machines
Our manufacturers directory includes companies that produce die-sinking EDM machines for metalworking.
The following terms are frequently searched for: Accutex die-sinking EDM machine, Agie die-sinking EDM machine, Charmilles die-sinking EDM machine, Exeron die-sinking EDM machine, GF die-sinking EDM machine, OPS Ingersoll die-sinking EDM machine, Mitsubishi Electric die-sinking EDM machine, ONA EDM machine, Sodick die-sinking EDM machine, Makino die-sinking EDM machine
Selecting the right die-sinking EDM machine
If you want to buy a die-sinking EDM machine, there are several important features and specifications to consider.
- When purchasing a die-sinking EDM machine, the most important factors are machining accuracy, surface finish, and positioning accuracy.
- The maximum electrode size, the travel distance of the axes, and the size of the working space are also important.
- The performance of the generator control (e.g., pulse duration, discharge energy) influences the cutting quality, machining speed, and electrode wear.
- The dielectric quality, the filter system, and the temperature stability also play a central role in process reliability.
- Another criterion is compatibility with CAD/CAM systems, as many electrodes have to be programmed individually.
- Those aiming for high volumes or unmanned operation should look for automation options such as pallet changers, electrode changers, or remote monitoring.
- Equally important: good service, spare parts availability, and training by the manufacturer.
Search now at maschinenauswahl.de for the die-sinking EDM machine that suits your production requirements.
Acquisition costs of a die-sinking EDM machine
(die-sinking EDM machine costs, die-sinking EDM machine price)
The acquisition costs for a new die-sinking EDM machine (e.g., a spark erosion machine or wire die-sinking EDM machine) can vary greatly depending on factors such as technology (wire vs. die-sinking EDM), degree of automation, machining size, precision, brand, and equipment. Specific prices are rarely disclosed publicly. If you want to purchase a new die-sinking EDM machine, you should probably expect to pay at least €150,000 to several hundred thousand euros – and possibly significantly more, depending on any special equipment.
Information about eroding and die-sinking EDM machines
This article answers the following questions, among others, and helps with the search terms mentioned:
- What does a die-sinking EDM machine do?
- What is a die-sinking EDM machine?
- What is EDM, explained simply?
- How accurate is die-sinking EDM?
- Die-sinking EDM machine function
- Voltage range of a die-sinking EDM machine