What is CNC Machining? The most accurate CNC mechanical processing

What is CNC Machining? The most accurate CNC mechanical processing

Apro Precision Machining Co., Ltd. has many years of experience in the field of prestigious CNC machining, mechanical processing workshops on demand nationwide. Since its establishment, the company has had a large number of customers trusting Apro’s services. Let’s find out CNC machining and what are the benefits of CNC machining in the following article.

Learn what CNC machining is?

CNC machining is a method of mechanical processing by applying modern CNC (computer numerical control) technology to achieve high accuracy and fast working speed.

In CNC machining, machines will remove material from a solid block to create a part based on a CAD, CNC model, optimizing the production cost of low to medium volume parts with advanced technology. manufactures parts with very tight tolerances and excellent material properties.

When it comes to CNC machining, there are two commonly used machining methods today: milling and cutting. You will have a better understanding of machining technology and operations of Milling and Lathe machines below.

How does CNC Milling work?

The most common CNC machine architecture is CNC Milling. In CNC milling, the parts are mounted on the table and the material is removed using rotary cutting tools.

Basic CNC Milling Process is as follows

  • The CAD model is converted into a sequence of commands to be understood. with CNC machine (G code). This usually uses the technical drawings provided and is done on the machine by the operator.
  • The block of material (also known as the workpiece) is cut to size and placed on the table for forming via a fixture or mounted directly on the table. The workpiece needs to be precisely positioned and aligned using special measuring tools to ensure accuracy during machining.
  • Material is removed from the block to shape the part using specialized cutting tools that rotate at very high speeds (thousands of rpm). To achieve precise forming, the workpiece is first roughed by rapid material removal with low precision (approximate shape). Then, one or more finishing-finishing toolpaths are used to form the final product.
  • If the model has locations where the cutting tool cannot be machined in a single pass (e.g. has a slot in the back), the part should be turned over and the steps above repeated.

After machining, the parts need to be bavia removed to eliminate minor defects. left on sharp edges due to material deformation during machining.

Most CNC milling systems have 3 linear degrees of freedom: X, Y, and Z axes. Nowadays more advanced systems with 5 degrees of freedom also allow the table or tool head to rotate (axis A and B). The 5-axis CNC system is capable of machining parts of high geometric complexity and can eliminate the need to use multiple machines.

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How does CNC turning work?

In CNC turning, the workpiece is mounted on a rotating chuck and the material is removed using fixed cutting tools. In this way, parts with symmetry along their central axis can be formed. Turning parts will be produced faster and cheaper than milling parts.

Using CNC turning to produce a

  • G-Code part generated from a CAD design and the workpiece of the right diameter is fed into the CNC machine
  • begins to rotate at high speed and the permanent cutting tool follows the programmed turning pattern, gradually removing material until the set part is reached. next. Holes along the center axis can also be machined, using a center drill and internal cutting tool.
  • If the part needs to be flipped or moved, the process is repeated. Otherwise, the part will be cut from the billet and ready for the next production steps.

Typically, CNC lathes are used to create cylindrical parts. Cylindrical parts can be manufactured using modern multi-axis CNC turning systems, which are also equipped with CNC milling tools. These systems combine the high productivity of CNC turning with CNC milling capabilities and can produce a very large range of geometries with loose rotational symmetry, such as camshafts and radial compressor rotors.

Especially for CNC programming for lathes because CNC lathes only include two axes to work with X and Z axis. In addition to CNC lathes, there are also many types of CNC machines on the market such as:

  • Milling
  • machine Grinding
  • machine Router machine: commonly used for wood industry
  • Plasma cutting machine ( plasma cutter)
  • Laser cutter (laser cutter)
  • Water cutter
  • (edm) Electrical spark processing (edm): including pulse shaping machine and wire cutting machine

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Features of machining CNC

  • Machine parameters

CNC machining machines have large working sizes. Milling systems can process parts as large as 2000 x 800 x 100mm (78” x 32” x 40”) and CNC turning systems produce parts with diameters up to Φ500mm (Φ20”)

. Machining parameters are defined by the machine operator during G-code generation and are generally of little interest to the designer. The machine parameters of interest are the machining dimension and the precision of the CNC machine:

With CNC machining, parts with high precision and tight tolerances can be manufactured. if no tolerance is specified, parts will be machined to a typical accuracy of ±0.125mm (±0.005”). Tight tolerances to less than half the diameter of an average human hair (±0.025mm or 0.001”) can be achieved with CNC.

  • CNC Cutting Tools

To create different geometries, CNC machines use different cutting tools. Here are some of the most commonly used milling tools in CNC:

Flat, cylindrical, and ball mills are used for machining slots, grooves, recesses and other vertical walls. Their different shapes allow for machining features with different parts. Cylindrical tools are also commonly used in 5-axis CNC machining to fabricate curved and freeform surfaces.

The cutter shaft diameter is smaller than the blade diameter, allowing these milling tools to cut T-slots and other cuts by removing material from the edges of the straight edge.

Drilling is a popular and fast way to create holes. In addition to standard sized bores, non-standard diameter bores can be formed by plane (spiral) milling tools.

CNC automatic tapping is used to produce threaded holes. To create a threaded hole, precise control of the rotational speed and feed rate is required. Manual taro is also still commonly used in some workshops.

Face mills are used to remove materials from large planes. Face mill diameters are larger than those of subsequent machining tools, so they require fewer toolpaths, reducing total machining time and producing flat surfaces. The face milling stage is often used early in the machining process to prepare workpiece dimensions.

Equally large cutting tools are used in CNC turning, covering all machining needs, such as faceting, threading and grooving.

Characteristics of CNC

Machining CNC machining is often used for metal, prototyping and mass production, plastic is often more difficult to machine because of its low melting point and lower hardness. Often plastic CNC machining is used in the prototyping process prior to plastic injection manufacturing. This is a strength of CNC machining when all materials can be machined by CNC method.

Design limitations and block complexity

Not all designs can be CNC machined. Design complexity increases production costs as more steps are required to complete a part.

CNC machining depends on the shape of the cutting tool. Tool access is also an obstacle in CNC machining. Material cannot be removed if the tool does not reach the area. CNC machines are using a 3-axis system, so the features must also be designed to be able to approach the workpiece directly from above. As a result, the 5-axis CNC system offers greater flexibility, allowing for more complex parts to be created, the angle between the part to be machined and the tool can be adjusted to machine even hard-to-reach parts. .

CNC Machining Materials

The physical properties of the material can affect the cost of the CNC machining process. Therefore, the cost of CNC machining materials is very different.

Material Characteristics
Aluminum 6061 Good weight-to-weight ratio


Low hardness

Brass C360 High ductility


machinability Good corrosion resistance

Stainless steel 304 Excellent mechanical properties

Corrosion resistance and acids excellent

Relatively difficult to work with

Nylon (PA6 and PA66) Excellent mechanical properties

High toughness

Poor moisture resistance

POM (Delrin) High hardness

Excellent thermal and electrical properties

Relatively brittle

ABS Excellent impact resistance Excellent

Mechanical properties Good

solvent sensitivity

Cold treatment and machining finish

Various cold treatments are used to smooth the surface of the part and improve resistance to abrasion or chemicals when machining CNC parts with knife marks on the product.

Advantages and Disadvantages of CNC Precision Machining


Using CNC materials with outstanding physical properties and adaptability in different environments and suitable for engineering applications

Major mechanical machining CNC precision for good accuracy and repeatability, can manufacture parts with very small tolerances

CNC machining is the most cost-effective manufacturing method for metal


partsThe nature of CNC machining is to remove the material on the workpiece, some blocks are very expensive or impossible to produce.

Due to the investment in machinery, the starting cost of CNC machining is very high.

Professional precision mechanical processing

Apro is a unit specializing in receiving precision CNC machining to ensure that your machining projects are completed with high precision. When receiving your machining needs, we will do CNC machining in a professional, timely manner with the highest accuracy.

Precision mechanical processing company with high precision and beautiful detailed surface quality, CNC Milling and CNC Turning machines are the first choice of customers. Depending on usage needs and business development orientation, factories or businesses can choose CNC machine brands depending on their respective features, quality and price.

With many years of experience in the mechanical industry, the mechanical processing company has gathered a team of professional, experienced staff with solutions and leading technical experts, always ready to support each customer in the near future. fastest time with optimal fit.

Customers coming to Apro will be consulted with appropriate CNC machining solutions as well as be assured of the international standard quality of the CNC machine brands that Apro distributes.

Not only confident in product quality, Apro also wins the trust of customers thanks to a technical team that is always available 24/7 to support you.

For inquiries about products and services, please contact Hotline: +84 774 168 999 for service support staff.