5 Common CNC Machining Techniques

CNC machining techniques allow creators to build products with a high degree of accuracy and detail. Using computer numerical control software, teamed with cutting implements and tools, enables these developers to limit the risk of human error in their designs, and create a highly sophisticated process that yields the best result. However, this isn’t just one single method. It’s an umbrella term that refers to a whole host of other techniques.

Choosing the right one is a matter of understanding the risk, benefits, and details of the various options. Some work best for more sophisticated projects, while others are ideal when adding finishing touches. By reviewing all the available features in CNC machinery, creators will be better prepared to take ownership of the product creation process.

5 CNC Machining Techniques and Their Pros and Cons 

While CNC machining generally refers to the overarching use of computer numerical coding to control tools, its application will change based on the types involved. Here are the five most common CNC machining techniques in use today.

1. Milling 

This process employs multi-point, rotating tools to cut and shape materials. The speed of rotation can reach thousands of RPMs a minute.  In this, the workpiece feeds to the milling tool rather than the tool coming to the piece.	Pros: Milling allows exceptional control over the cutting of materials and can remove a lot or a little at a time.
	Cons: CNC programming in milling machines is very complex and is typically only done by the most skilled operators.

2. Turning 

A stationary tool trims away excess material from a rotating workpiece. The piece that holds the workpiece and rotates it is called a lathe	Pros: Turning can be ideal for high-volume situations where many parts or pieces are required.
	Cons: Shapes are typically limited to cylindrical types like spheres and cones.

3. Electrical discharge machining 

Electrical discharge machining, or EDM, uses electric sparks to melt and shape metal without the need to cut a piece. There are two main types of EDM: wire EDM and die-sink EDM.	Pros: This is ideal when a material is fragile and can not stand up under heavy cutting.
	Cons: This is a lengthy process that is mainly designed for finishing touches, not complete projects.

4. Grinding 

A rotating grinding wheel moves against the surface of a piece to shape it. The function is somewhat similar to milling, though grinding does not employ cutting tools.	Pros: This process creates a high-quality surface, making it ideal as a finishing tool.
	Cons: This is a slow process as no cutters are involved, and material is removed through abrasion instead.

5. Drilling 

A drilling process in CNC machining is somewhat self-explanatory. It makes use of drills to create precise holes and chip away at excess materials.	Pros: Drilling is an economical and somewhat easy process when compared to other CNC machining techniques.
	Cons: Application may be limited without a tool turret to change drill bits as needed.

In addition to the five above categories of CNC machining, each may have their own subcategories of tools which are useful for various parts of new product development. As a result, creators must work with partners experienced in all the various applications of CNC machining.

Choosing the Right CNC Machining Process 

Often, it’s not a matter of choosing a single CNC machining technique for the creation of a product—instead, it’s about developing a process that uses several methods in the right order. The capabilities of shops can vary widely across the industry. Choosing a partner with access to a wide range of tools is best.

Aside from those techniques, it’s also vital to look at the software that controls these machines, as they are what guide the product design. There is a variety of computer-aided design and manufacturing software (CAD and CAM) available on the market, so some programs are more robust than others. Some are targeted at beginners, which makes them unsuitable for major commercial usage that most creators need for their products. Among professionals, software like Mastercam is considered more appropriate for creating products for the mass market.

Ideally, creators will be able to tour the shop of their preferred company and even see some CNC machining techniques in action. This up-close look will help them determine which partners are right for them and gain confidence in the process. The right one will have a wide variety of options to share to ensure the best, most precise designs and manufacturing plans.