CNC Milling: 3D, 4D, 5D, Technologies, Processes and Industrial Application

CNC Milling: 3D, 4D, 5D, Technologies, Processes and Industrial Application

CNC milling is an advanced machining method that involves the precise shaping of materials using a computer-controlled milling machine. In this article, we will discuss the basics of CNC machining, the origins of this technology, the milling process, the construction and design of a CNC milling machine and the principles of computer control.

The origins of CNC milling: a brief historical overview

The origins of CNC milling date back to the 1950s, when the first numerical systems were introduced to control machine tools. Since then, the technology has evolved, bringing ever-increasing precision, speed and machining capabilities. Today, CNC milling is widely used in various industries, such as automotive, aerospace and medical.

CNC milling process: from design to finished product

The CNC milling process begins with the creation of a 3D design in specialised CAD software. The design is then converted into machine language that the milling machine can understand. In the next stage of the machining process, the material is clamped onto the milling machine’s work table and the computer-controlled milling machine precisely removes layers of material, shaping it according to the design. Once machining is complete, a finished product is created that can be subjected to further processes such as polishing or painting.

CNC milling machine's construction and design: key elements

The construction of a CNC milling machine includes several components, such as the work table, on which the material to be machined is mounted; the spindle, which drives the cutting tool (cutter); and the axis system, which allows the tool to be moved precisely relative to the material. The design of a CNC milling machine can vary depending on its purpose and the number of axes, but the operation principle remains the same.

Computer control in a CNC milling machine: functionality

Computerised control in a CNC milling machine involves converting data from the CAD design into machine language that the machine can understand. This control is carried out using specialised systems such as Fanuc control, which ensure precise and reliable machine operation.

Types of CNC milling and technologies used

In CNC machining, we distinguish between several types of milling, which differ in their technology and applications.

3D, 4D and 5D milling: differences and applications

3D milling is the primary CNC machining method that allows material to be shaped in three axes (X, Y, Z). 4D milling adds to this the ability to rotate around one of the axes, allowing more complex shapes to be machined. 5D milling, on the other hand, allows machining in five axes. 5D milling is particularly useful in industries such as aerospace and automotive.

Face milling and concurrent milling: characteristics and applications

Face milling consists of removing material through the cutter in a motion perpendicular to the work surface. This method is mainly used for grooves, gouges or shaping edges. In co-rotating milling, the cutter moves parallel to the work surface, allowing for the surface to be smoothed and grooves or gouges of varying depths to be made. Co-rotating milling is often used in the machining precision components, such as bearings or shafts.

Conventional versus CNC milling: comparing the methods

Conventional milling is a traditional machining method that involves manual control of a milling machine by an operator. Compared to CNC milling, this method is less precise, slower and more labour-intensive. CNC milling, on the other hand, allows the process to be automated. As a result, CNC milling is now the preferred machining method in many industries.

Materials for CNC milling

CNC milling materials cover a wide range of different materials that can be machined. In this section, we will discuss in detail CNC milling of aluminium, brass, plastics and the shaping of materials using this technology.

CNC milling of aluminium and brass: specifications and applications

CNC milling of aluminium and brass are popular methods for machining these materials, which have good mechanical properties, thermal and electrical conductivity along with corrosion resistance. CNC milling allows for the precise shaping of aluminium and brass components that are used in various industries such as automotive, aerospace, electronics or construction.

The specificity of CNC milling of aluminium and brass lies in the use of appropriate tools and machining parameters that ensure high surface quality and dimensional accuracy. In the case of aluminium, it is also important to use appropriate lubricants and coolants that minimise the risk of overheating the material and the formation of scales.

CNC milling of plastics: possibilities and limitations

CNC milling of plastics is another machining method that allows parts to be shaped from different types of plastic, such as polycarbonate, polyamide, ABS or PTFE. CNC milling of plastics offers many possibilities, such as precise shaping, low tool wear and the possibility of machining materials with different mechanical, thermal or chemical properties.

The limitations of CNC milling of plastics are mainly due to material properties such as low temperature resistance or a tendency to deform under stress. Therefore, it is important to use appropriate tools and machining parameters that minimise the risk of material damage and ensure high surface quality and dimensional accuracy.

Shaping materials using CNC milling

Shaping materials using CNC milling involves removing layers of material using cutting tools that move along defined trajectories. CNC milling allows various materials such as metals, plastics, wood or composites to be shaped with high precision and repeatability.

Depending on the type of material and the requirements for surface quality and dimensional accuracy, CNC milling can be carried out using different techniques such as face milling, co-rotating, 3D, 4D or 5D milling.

The industrial application of CNC milling technology covers many sectors. These include industries such as:

  • automotive – manufacturing automotive parts such as engines, gearboxes and suspension components,
  • aerospace – manufacturing complex aircraft structural components, aircraft engines and avionics systems,
  • electronics – machining of housings, heat sinks or mounting components for electronic devices,
  • medicine – manufacturing implants, surgical instruments and medical equipment components,
  • power engineering – manufacturing of wind turbine parts, solar turbine parts and power plant components,
  • mechatronics – manufacturing of machine parts and devices for various industries.

In each of these sectors, CNC milling allows the precise shaping of components in different materials, such as metals, plastics or composites, with high repeatability and surface quality.

Mass, single unit and batch production: where is CNC milling important?

Mass production is the process of producing large quantities of identical products with a strong emphasis on fast and precise processing of components with minimal human input.

Single unit production involves the manufacture of individual products, often to a customer’s special order. It is characterised by the ability to quickly and precisely shape parts with complex geometries and the flexibility to change machining parameters.

Batch production is the process of manufacturing a limited number of identical products, where the demand is for high quality and repeatability of parts at reduced costs.

Advantages and challenges of CNC milling

The advantages of CNC milling primarily include the process’ precision, production accuracy and the automation possibility. However, the technology also brings with it some challenges, such as the costs associated with purchasing and maintaining machines, and the need for skilled staff.

CNC automation: benefits and challenges

CNC automation makes it possible to increase production efficiency, reduce errors and minimise human involvement in the machining process. With automation, CNC machines can run for longer periods of time without constant supervision. However, automation also brings with it some challenges, namely these are:

  • the investment in advanced machinery and software,
  • the need to train staff in the operation and programming of CNC machines,
  • maintenance and servicing of the machines.

Precise process and production accuracy: advantages of CNC milling

Precise process and production accuracy are among the main advantages of CNC milling. Thanks to computer control, CNC machines are able to perform complex operations with a high degree of precision, which translates into high quality manufactured parts. In addition, CNC milling allows for the reduction of errors due to human factors, high process repeatability and flexibility in changing machining parameters.

Price of CNC milling: factors influencing service costs

The price of CNC milling depends on many factors, such as:

  • the type and size of the material to be machined,
  • the number of machine axes and the degree of its technological advancement,
  • the time required to complete the job,
  • costs connected with maintenance and servicing of machines,
  • experience and qualifications of the personnel operating the CNC machines.

CNC milling orders: what is the process like?

The process of ordering CNC milling begins with the preparation of a technical design, which includes information on dimensions, tolerances and the material to be used to make a part. The customer then sends the design to the company offering CNC milling services, which analyses the order and prepares a quote. Once the price quote is accepted, the company proceeds with the order and, once the machining is complete, the finished parts are sent to the customer. This process can also include additional services such as part assembly or painting.


CNC milling is a precise and automated process that allows fast and accurate machining of various materials such as aluminium, brass or plastics. The technology is used in many industries such as automotive, aerospace or medical.

When choosing professional CNC milling services, it is worth paying attention to the technological advancement of the machines, the staff’s experience and the quality of the parts made. The pricing of CNC services should take into account the cost of the material, the order’s execution time and possible additional services, such as assembly or painting of the elements.

We encourage you to familiarise yourself with the rich milling services offer at CPP “PREMA” S.A., as well as to contact us and cooperate in the creation of a wide range of high quality galvanic products.