Wire EDM vs Sinker EDM: Differences, Pros and Cons

Electrical discharge machining (EDM) is a non-conventional material removal process. An electrical energy in a form of sparks cut off the material from workpiece. The two common types of this techniques are sinker and wire EDM. These machining methods are distinct yet relatable methods that have unique features and advantages.

This article will highlight their core features, design capabilities and their differences to provide a clear understanding for better selection. This information would be beneficial for manufactures to understand the complex background of machining processes.

What is Electrical Discharge Machining (EDM)?

EDM is also called spark erosion or machining process. It is a non-conventional precision technique of material removal for less workpiece thickness by using electrical energy. Unlike the other machining processes, it is a non-contact machining between the tool and object and is ideal for delicate parts and tough material like tungsten or titanium.

Overview of EDM and How It Works

EDM uses controlled electrical sparks to remove material from the object and create a desired shape. It has design capabilities for machining hard materials in which two electrodes, a tool and a workpiece electrode, separated by dielectric fluid are used. Electrical discharge of low current and high voltage is produced between these electrodes and generate high heat. This heat melts the material at the point of spark and creates a crater. Dielectric fluid removes the melted material and cools down the workpiece. It is an insulator between the electrodes. Electrodes are not in contact with each other, which eliminates chatter and vibration issues.

Why EDM is essential for high-precision machining

EDM provides high precision by controlling the voltage, current, time and the movement of wire electrode. It gives a precise shape, and intricate features can easily be created in the workpiece.

What are Three Types of EDM?

The three types of EDM are:

• Die-Sinking EDM:it has a pre-formed electrode which generate cavities or shapes in the material.
• Wire EDM:it has a thin wire electrode to form intricate shapes, slots and complex geometries for less workpiece thickness
• Hole Drilling EDM:it has a pulsing electrode which generate small and deep holes

a) Wire EDM, b) Sinker EDM, c) hole drilling method

What is Sinker EDM?

Sinker EDM is also called plunge EDM or cavity EDM. It uses a shaped electrode to create precise and complex cavities. A spark erosion submerged in a dielectric fluid generates cavities in conductive materials.

How does Sinker EDM Work?

An electrode of copper, graphite or tungsten is used to shape or create cavities. Workpiece and electrode both are sunk in dielectric fluid and high voltage is applied between them. This creates a tiny spark that erodes the metal. The spark melts the material creating cavities and creates shape.

What is Sinker EDM Used for?

Sinker EDM is well known for its capability to make very precise and complex shapes. It has design capabilities for hard-to-machine material like tungsten carbide or tool steel. There is no physical touch between the workpiece and electrode which maintains the integrity of the material. It is excellent at creating complex geometries like sharp corners, irregular shapes and deep ribs.

Why Sinker EDM is Ideal for Hard-to-Machine Materials

It has design capabilities for making molds and dies for stamping and plastic injection molding. It is also used for manufacturing tooling like punches, dies and most importantly for aerospace and medical parts with complex geometries.

What is Wire EDM?

Wire EDM is also called cire-cut EDM. It is a precise manufacturing process for less workpiece thickness which uses thin electrically charged wire electrode to cut the metal. A spark is generated that erodes the metal and creates complex and intricate designs. The shape created has higher accuracy and minimal distortion.

Definition and working principle of wire EDM

A thin wire acts as an electrode and moves along near the workpiece. This charged wire creates sparks between the electrode and workpiece which are sunk in dielectric fluid. This fluid removes the eroded metal and cools the workpiece. This process is non-contact machining which helps prevent distortion.

Sinker EDM Electrode Material

The commonly used electrode material in sinker EDM is copper, graphite and their alloys like copper-tungsten because they are highly electrically conductive and can survive erosion

Wire EDM Applications

Wire EDM is a versatile process for less workpiece thickness. It can efficiently create precise cuts and shapes, molds and other parts which have tight tolerance for different industries like medical, automotive, aerospace and electronics. It is ideal for creating prototypes and custom parts which require fine detail and intricate details.

Advantages and Disadvantages of Sinker EDM

Sinker EDM is a versatile technology which has many advantages and some limitations.

Advantages of Sinker EDM

The advantages of sinker EDM are explained below:

• It excels at generating complex and intricate shapes, cavity machining, deep ribs, sharp corners which are used in mold and die casting.
• It can efficiently machine hard materials like tool steel
• It can obtain high precision and tight tolerance for complex shapes.
• It is a non-contact machining method which minimizes deformation and stress in material
• It is versatile for tooling to make mold, dies, complex 3D geometries and for rapid tooling applications

Disadvantages of Sinker EDM

The disadvantages of sinker EDM are as:

• It is an expensive technique for maintaining electrodes and is time consuming
• Electrodes can wear out and require replacement time and additional cost
• The technique can erode the electrode which requires multiple machining
• It can consume a large amount of energy during work
• It is not ideal for thin and light parts.

Advantages and Disadvantages of Wire EDM

Wire EDM has many advantages but also have some limitations

Advantages of Wire EDM

The advantages of wire EDM are:

• It can achieve tight tolerance and higher precession for intricate designs
• It can cut through hard and tough material
• Thin wire helps to create thin walls, small radii and thin slots in workpiece
• It generates less heat and has low risk of heat affected zone and distortion
• It has burr-free edges and does not require additional finishing processes
• It is versatile and can be used for small as well as large parts
• It is suitable for mass production because of offering automated control and repeatability.

Disadvantages of Wire EDM

The disadvantages of Wire EDM are as:

• It is relatively slower than other machining processes.
• It requires high initial investment and is overall a costly process
• It is limited to only electrically conductive materials
• Wire breakage can interrupt the cutting process which slows the lead time.
• Oxidation can occur on some material which requires additional cleaning
• Specialized skills and training are required to run the program of wire EDM

What is the Difference Between Wire EDM and Sinker EDM?

The key differences between wire EDM and Sinker are as:

Machining Process

Wire EDM used thin wire as an electrode that moves along the workpiece and creates electrical spark to melt the metal. While sinker EDM has a shaped electrode and dielectric fluid that is lowered into workpiece and create spark to remove erosion and cut the desired shape.

Geometry and Design Capabilities

Wire EDM is ideal for tight tolerance and fine machining details in complex 3D geometries and high-precision parts. Sinker EDM is used for cavity machining, molds and dies and for 2D cutting profile.

Tooling Requirements

Wire EDM is versatile and uses standard electrode wire. Sinker EDM used custom electrode for each operation

Surface Finish and Precision

Wire EDM is ideal for straight cuts and gives high accuracy. While sinker EDM has superior finish for complex shapes and does not require any additional finishing operation.

Cost Considerations

Wire EDM offers low cost for simple parts while Sinker EDM is an expensive process which requires higher initial cost and custom electrodes.

Table of Difference Between Wire EDM and Sinker EDM

The differences between wire EDM and sinker EDM are briefly explained in the table

Similarities Between Sinker EDM and Wire EDM

Both processes share some same features which are discussed below:

Core Principles Shared by Both Processes

Both are electrical discharge machining processes and used electrical spark for material removal. A dielectric fluid and electrode cut shape precisely in workpiece

Applications Shared by Sinker EDM and Wire EDM

Both techniques are well known for high precision and accuracy in intricate parts that are made for aerospace, medical devise and automotive parts. Both are used for conductive material like steel, aluminum and titanium and their alloys.

Sinker EDM vs Wire EDM: Which Should You Choose?

There are some factors to consider when selecting any technique

Key Factors to Consider

Sinker EDM is ideal for thicker material and for intricate shapes, mold, dies and deep ribs. Wire EDM is best for gentle material and for complex shapes with small and tight tolerance.

Wire EDM is a fast and cost-effective process and is best for higher production quantities.

Sinker EDM is slower, expensive and is best for lower production.

Best Use Cases for Each Process

Sinker EDM is used for plastic injection applications and for mold making, dies and deep cavity machining. Wire EDM is best for rapid prototyping, high precision parts and parts with fine machining details.

Sinker EDM and Wire EDM Tolerances

The tolerances of sinker EDM and Wire EDM are compared below:

Tolerances of Sinker EDM

Sinker EDM is used for extremely high tolerance value which can be as low as 0.005mm and is best for applications where high precision and accuracy are required

Wire EDM Precision

Wire EDM is more suitable for relatively lower tight tolerance than sinker EDM but can achieve tight tolerance for thin walls and smaller radii.

Sinker EDM and Wire EDM Machining Applications

Sinker EDM and Wire EDM both are versatile methods and have uses in many fields.

Aerospace and Automotive

• Both are used in making mold, dies, tooling, for hard material like tool steel for aerospace and automotive applications
• Both can make precise engine parts for automobiles and aircraft.
• Both can create intricate metal parts for high temperatures applications

Electronics and Medical Device Manufacturing

• Both are suitable for creating dies and mold for medical devices and tools
• These are used in manufacturing surgical tools and orthopedic implant with fine machining details
• Both can create complex shapes in hard materials.
• Both can produce parts with tight tolerance and ultra-high precision.

Sinker EDM vs Wire EDM VS CNC Machining for Fine Features and Thin Walls

Wire EDM is best for creating fine machining features and thin walls with higher precision, especially in hard materials.

What is the Diameter of the Holes you are Making?

Wire EDM is well-suited for holes with micro-level accuracy. It can produce small holes, thin walls, fine machining details and high surface finish.

Sinker EDM vs Wire EDM VS CNC Machining for Parts Manufacturing Process

Sinker EDM is best for creating complex 3D geometries and wire EDM is ideal for precise 2D cutting. While CNC machining offers versatile features for material removal and creating shapes.

Conclusion: Choosing the Right EDM Process for Your Project

Wire EDM utilizes thin wires to remove material and create intricate shapes in 2D cutting. Sinker EDM uses a wire electrode to create cavities in complex 3D geometries. Both are used for high precision and accuracy. Both are versatile methods and can be used for many applications depending on the requirements. If you are looking for efficient supplier and services for any EDM project, Tuofa CNC machining service offers best service in China. Tuofa has years of experience, skilled staff, experienced engineers and advanced technologies to provide high quality services in precision metalworking techniques used for creating parts with tight tolerance and higher accuracy

FAQs about Sinker EDM and Wire EDM

Which is Better: wire EDM vs Plunge EDM?

Wire EDM is best for precise profile cutting and Plunge EDM is best for creating complex 3D geometries

Why choose sinker EDM for mold making?

Sinker EDM is best for intricate cavity machining and hard material machining. It can create complex shapes, deep ribs and sharp internal corners.

Wire EDM Alternative

Wire EDM alternatives for precise cutting applications are laser cutting and waterjet cutting

What is the Cost Difference between sinker EDM and wire EDM?

Wire EDM is less expensive than sinker EDM and is faster and requires less customization as the sinker EDM used custom electrode for each project.