Types of EDM Machining and Their Differences

What is EDM?

EDM is a way to cut metal. It uses sparks. The sparks make the metal melt. It is good for hard metals. It can make small parts. It does not touch the metal.

EDM works with electricity. The sparks jump from a tool to the metal. The sparks make tiny holes in the metal. This cuts the metal bit by bit.

Why Use EDM?

• It can cut very hard metal
• It makes clean cuts
• It can make small holes
• It does not push on the metal
• It is good for thin parts

The 3 Big Types of EDM

There are three main types of EDM. Each one does a different job. Let’s look at all three!

1. Wire EDM

Wire EDM uses a thin wire. The wire is like a string. It has electricity in it. The wire cuts through the metal like a hot knife.

How Wire EDM Works:

• A thin wire (like a hair) moves through the metal
• The wire has sparks jump from it
• The metal sits in special water
• The water helps clear away tiny metal bits

What Wire EDM is Good For:

• Making flat parts with fancy shapes
• Cutting thin metal
• Making very small parts
• Making gears
• Making tools for doctors

Good Things About Wire EDM:

• It is very exact (±0.0001″)
• It makes smooth cuts
• It can cut hard metals
• It does not need special tools

Not So Good Things:

• It is slow for thick metal
• You need to buy new wire a lot

Wire EDM is best when you need very exact cuts in flat metal. It works at a speed of about 0.5-6 in²/hr.

To learn more about precision machining methods, check out our services.

2. Sinker EDM

Sinker EDM uses a tool that is the shape you want to make. The tool goes into the metal and makes a hole that matches the tool’s shape.

How Sinker EDM Works:

• A tool (made of graphite or copper) is shaped like what you want
• The tool moves down into the metal
• Sparks jump from the tool to the metal
• Special oil helps wash away the tiny metal bits

What Sinker EDM is Good For:

• Making deep holes
• Making 3D shapes in metal
• Making molds for plastic parts
• Making car parts

Good Things About Sinker EDM:

• It can make complex 3D shapes
• It works on very hard metals
• It can make deep cuts

Not So Good Things:

• The tools wear out
• You need to make a new tool for each new shape
• It is slower than Wire EDM

Sinker EDM is best when you need to make deep, fancy shapes in metal. It is used a lot for making molds and dies.

For specialized sinker EDM services, visit our sinker edm machining page.

3. Hole Drilling EDM

Hole Drilling EDM makes small, deep holes. It uses a spinning tube to make the holes.

How Hole Drilling EDM Works:

• A hollow tube spins fast
• The tube has electricity in it
• Sparks jump from the tube to the metal
• Special water goes through the tube to wash away tiny metal bits

What Hole Drilling EDM is Good For:

• Making very small holes (less than 1mm)
• Making deep holes
• Making air holes in jet engine parts
• Making fuel holes in car parts

Good Things About Hole Drilling EDM:

• It can make very deep holes
• The holes are very straight
• It works on very hard metals

Not So Good Things:

• It can only make round holes
• It is slower than drilling

Hole Drilling EDM is best when you need very small, deep holes in hard metals. It works at a speed of about 0.1-0.5 mm/min.

Big Differences Between Wire EDM and Sinker EDM

Let’s see how Wire EDM and Sinker EDM are different:

When looking at aerospace applications, our aerospace edm services use these differences to choose the right process.

How to Pick the Right EDM Type

Here’s how to choose which EDM is best for your job:

1. Look at How Thick the Metal Is

• Thin sheets → Use Wire EDM
• Thick blocks → Use Sinker EDM or Hole Drilling EDM

2. Look at What Shape You Need

• Flat shapes → Use Wire EDM
• 3D shapes with holes → Use Sinker EDM
• Just small holes → Use Hole Drilling EDM

3. Look at How Exact It Needs to Be

• Need super exact cuts → Use Wire EDM (±0.0001″)
• Need good but not perfect cuts → Use Sinker EDM (±0.001″)

4. Look at Your Money

• Small jobs → Use Wire EDM (less setup cost)
• Big jobs → Use Sinker EDM (less cost over time)

Where Each EDM Type is Used

Different jobs need different EDM types:

Planes and Jets:

• Hole Drilling EDM → Makes cooling holes in jet parts
• Wire EDM → Makes exact parts for plane motors

Doctor Tools:

• Wire EDM → Makes sharp tools for doctors
• Sinker EDM → Makes tool shapes for medical parts

Cars:

• Sinker EDM → Makes molds for plastic car parts
• Wire EDM → Makes metal parts for car engines

Tool Making:

• Both Wire and Sinker EDM → Make tools that make other parts

Questions People Ask About EDM

For complex parts that need both EDM and traditional machining, our complex cnc machining services can provide integrated solutions.

EDM vs Other Ways to Cut Metal

EDM is just one way to cut metal. Here’s how it’s different:

EDM vs Cutting Tools:

• EDM doesn’t touch the metal – it uses sparks
• Cutting tools push on the metal – they can bend thin parts

EDM vs Laser Cutting:

• EDM can cut thicker metal than lasers
• Lasers are faster but make hot spots that can bend metal

EDM vs Water Jet:

• EDM makes smoother cuts
• Water jets are faster but not as exact

Sum Up

EDM is a great way to cut metal using sparks. The three big types are:

1. Wire EDM – Uses a thin wire to make flat, fancy shapes
2. Sinker EDM – Uses a shaped tool to make 3D shapes
3. Hole Drilling EDM – Uses a hollow tube to make small, deep holes

Each type is good for different jobs. Pick the right one by looking at:

• How thick the metal is
• What shape you need
• How exact it needs to be
• How much money you have

EDM is best for hard metals, exact cuts, and fancy shapes that other cutting ways can’t make.