CNC Guide: What is CNC Milling?

If technology is always improving, then CNC milling will never stop. In today's society, many products we use in our lives are inseparable from CNC milling. The smartphones, cars, drones, and other products you see have some parts from CNC milling. It can be said that CNC milling is an ideal method for mass production of metal and plastic parts.

In this guide, we will take you through the relevant processes of CNC milling technology from multiple perspectives. If you are interested in manufacturing or you are working in a related field, then this CNC milling guide blog is definitely worth a look.

What is CNC milling?

Definition and background of CNC milling

CNC milling refers to the mechanical processing process of removing excess parts from raw materials by using computer control systems to obtain the desired CNC parts. According to historical records, CNC milling technology originated in the late 1940s. The initial application direction was the aviation industry. As time went by, it gradually developed into various mechanical industry sectors today.

For modern manufacturing, CNC milling is of great significance. With the advent of the Industrial 4.0 era, it has promoted the automation and integration of the manufacturing industry to a certain extent.

How does CNC milling work?

CNC milling is an upgraded process based on traditional milling. As one of the processing methods of subtractive manufacturing, it has many different unique features.

For easy understanding, we break down the working steps of CNC milling into the following parts for a detailed explanation:

Step 1: CAD file analysis

The CNC programmer will analyze the processing drawings you provide. Generally, the following key information will be extracted:

1. The size of the part (this is the key feature)

2. The specific number of holes

3. Tolerance requirements

4. Priority processing points

5. Think about the solution to the position that the tool cannot reach

Step 2: Write the actual tool path

This link is very important, it determines the tool usage rate in the actual CNC milling process. If it is not written well, the actual processed parts will not only be very rough in detail but also often break the tool. This is a great test of the level of a CNC programmer.

Step 3: Copy and operate

When the CNC programmer completes the programming of the part, the tool path data will be handed over or copied to the CNC machinist in the next link, who will start the machine and perform the CNC processing process according to the corresponding program until the part is completed.

What are the common types of CNC milling operations?

In the CNC manufacturing industry, there are many metal processing methods for CNC milling. These milling processes are suitable for processing various planes, grooves, special-shaped surfaces and other part shapes. They are highly efficient and diverse. The following are several common types of CNC milling:

1. Face milling: This is the most common type of milling operation and is suitable for large-area flat processing. Face milling cutters have multiple interchangeable blades that can efficiently process the required surface and obtain a high surface finish.

2. Ordinary milling: Also known as slab milling, it is used to produce flat and horizontal surface processing. The teeth of ordinary milling cutters are located on the periphery, allowing machinists to perform cutting operations. The operation is simple and suitable for large-scale production.

3. Angular milling: Similar to ordinary milling, the axis of the cutting tool is at a certain angle to the workpiece surface. Flexible and changeable, suitable for making grooves, saw teeth, chamfers, and other features.

4. End milling: Mainly used for processing step surfaces of about 90 degrees. End milling is similar to face milling, but the angle of the circumferential cutting edge plays a decisive role, with high efficiency and suitable for precision processing.

5. Contour milling: used to process free-form surfaces (such as arc surfaces), suitable for processing complex-shaped assembly parts such as molds.

What parts can be made by CNC milling?

The process of CNC milling is diverse and complex, and it can produce many types of parts. For example, we often see plane parts, variable angle parts, curved parts, and complex mechanical parts.

Not only that, CNC milling is widely used in various fields, including:

Machinery parts: such as gears, bearing seats, couplings, pump bodies, valves, etc. 

Aerospace parts: such as aircraft engine parts, aircraft structural parts, spacecraft structural parts, etc. 

Auto parts: such as automobile engine parts, automobile chassis parts, automobile body parts, etc. 

Mold parts: such as plastic molds, die-casting molds, stamping molds, etc. 

Electronic parts: such as circuit boards, radiators, connectors, etc. 

Medical device parts: such as surgical instruments, prostheses, orthotics, etc. 

Crafts: such as wood carvings, stone carvings, metal crafts, etc.

Although the characteristics and processing requirements of these parts are different, CNC milling can meet their requirements of precision and complexity.

What materials can CNC milling machines process?

The power of CNC milling machines lies in that, in most cases, it is not affected by the processing materials, which means that it can process many materials, such as metals, plastics, wood, composite materials, etc.

Many materials are most suitable for CNC milling, including but not limited to the following:

Metals: such as various carbon steels, alloy steels, aluminum alloys, copper, stainless steel, etc. These metal materials are widely used in machinery, automobiles, and various aerospace fields.

Plastic materials: CNC milling machines can also process many plastic materials, such as common PA, ABS, PS, PC, etc. These materials are often used in medical, drone, automotive, and other related consumer goods industries due to their unique easy-to-form, and durable properties.

Wood: In the construction industry, CNC milling wood is the most, or various daily necessity.

Composite materials: Composite materials are also widely processed by CNC milling machines due to their high strength, lightweight, and corrosion resistance. Common composite materials include carbon fiber, glass fiber, etc., which are mainly used in aerospace and sports equipment manufacturing.

Do you provide CNC milling services?

We are a parts processing manufacturer with CNC machining as its core. We can provide you with professional and affordable CNC milling services, and the quality of product parts is guaranteed. If you have a parts project production demand, you can upload your CAD file and our professional engineers will provide you with a free quotation.

Summary

In this guide, we introduced the definition, background, working principle, and more of CNC milling. This section has many special terms. If you are interested in the CNC industry and are passionate about this job, then all the contents of this guide should be a good "gift" for you.

If you want to know more exciting content, please feel free to follow our blog series, we will update it from time to time. Finally, thank you for reading.

CNC milling FAQ

Is milling the same as CNC milling?

The two are essentially the same, but CNC milling is more accurate and efficient. Not only that, CNC milling can manufacture more complex parts.

What is the minimum and maximum size that CNC milling can manufacture?

The minimum size that CNC milling can manufacture is 0.1mm, while the maximum size depends on the specifications of the machine tool and the size of the tool. ‌

Is the price of CNC milling expensive?

The processing cost of CNC milling depends on many factors, depending on the design the complexity of the part shape, the use of materials, etc. Usually, the cost of parts manufactured here at RT is more reasonable.