CNC machined parts play an important role in modern manufacturing. Starting from the basic machining principles, it involves the precise operation of machine tools, covering milling, turning, drilling and other processing techniques, and has specific processing methods for different materials such as metals, plastics, composite materials, etc. I will systematically and professionally analyze the relevant knowledge of CNC machined parts for you to help you deeply understand this key area.
What Is CNC Machining?
CNC, or computer numerical control, is a technology that uses digital information to control the movement and processing of machine tools. Its principle is to convert the designed part drawings into digital codes, and accurately direct the machine tool tools to perform processing operations through the computer control system, thereby achieving high-precision and automated processing of parts, reducing human errors, and improving production efficiency and product quality.
When a customer needs me to process a complex part, CNC machining allows me to precisely control each step of the operation according to the drawing. For example, I once processed precision parts for a medical device company that required extremely high dimensional accuracy. Through CNC technology, the entire machining process is automated, reducing deviations from manual operations and ensuring high precision and consistency of parts.
Multiple Types Of CNC Machined Parts
In CNC machining, various processes are brilliant and colorful, which together help to form precision parts. Milling technology can realize the fine processing of planes, contours and cavities , turning focuses on the processing of rotating bodies , drilling and boring are good at hole processing , EDM can create complex molds und laser cutting and processing have unique advantages in thin plates, engraving and punching.
Next, let’s take a closer look at these CNC machining processes categorized by technology and materials :
By Technology
Milling Process
When we mill, the milling cutter rotates at high speed as the main motion, and the workpiece performs the feed motion. For example, when processing a complex cavity of a mold, we need to accurately control the motion trajectory of the milling cutter in the X, Y, and Z axes according to the three-dimensional model of the mold through the CNC system. The milling cutter blade gradually cuts the workpiece material, and the material removal rate can be accurately controlled within a certain range, such as 10-100 cubic centimeters per minute, so as to process various shapes. For example, the common mold cavity depth can reach 10-50 mm, and the contour accuracy can reach ±0.05 mm.
I know that many mechanical parts and molds require complex shapes and high-precision dimensions, such as automobile engine block molds. The milling process can achieve complex three-dimensional shape processing, meet the strict requirements of these parts on accuracy and shape, ensure the precise dimensions of each chamber of the engine block, improve the power performance and reliability of the engine, and compared with traditional processing methods, it can greatly shorten the processing cycle, improve production efficiency, reduce costs, and enhance the competitiveness of products in the market.
Turning Technology
Generally, during the turning process, the workpiece rotates as the main motion, and the turning tool performs linear feed motion. For example, if we need to process a precision shaft part with a diameter of 50 mm and a length of 300 mm, we should set the spindle speed of the lathe to 1000 – 3000 rpm according to the material and tool . By accurately controlling the feed rate of the turning tool (such as 0.1 – 0.5 mm/rev), we can ensure that the cylindricality of the shaft is within ±0.005 mm, the roundness error is less than 0.003 mm, and the surface roughness reaches Ra0.8 – Ra1.6 microns, ensuring the dimensional accuracy and shape accuracy of the shaft.
I have handled a large number of shaft parts such as motor shafts and machine tool spindles in some mechanical manufacturing , and I found that the rotation accuracy will directly affect the performance of the equipment. However , turning technology can ensure the high-precision rotation characteristics of shaft parts, reduce the vibration and energy loss of equipment during operation, and improve the stability and service life of equipment. For example, turning of high-precision machine tool spindles can increase the processing accuracy of machine tools by an order of magnitude, meeting the needs of high-end manufacturing fields such as aerospace and precision instruments for high-precision shaft parts.
Drilling And Boring
Drilling is the process of drilling holes on a workpiece through the rotation of the drill bit. For example, I use a twist drill to drill a hole in a 20 mm thick steel plate. The drill speed can reach 1000 – 2000 rpm, and the feed rate is 0.1 – 0.3 mm/rev, which can quickly drill a hole with a diameter of 5 – 20 mm.
Boring, on the other hand, uses a boring cutter to further improve the accuracy and surface quality of an existing hole. For example, when boring a piston hole with a diameter of 80 mm on an engine block, the radial feed amount of the boring cutter is precisely controlled (0.05 – 0.1 mm) to achieve a hole cylindricity of ±0.01 mm and a surface roughness of Ra0.8 – Ra1.6 microns, ensuring a good fit between the piston and the hole.
I learned that in many mechanical equipment, the precision and quality of hole parts are crucial. For example, the piston hole of the engine cylinder block, high-precision holes can ensure the sealing between the piston and the cylinder block, improve the combustion efficiency of the engine, reduce fuel consumption and exhaust emissions. In precision machining, accurate hole positions and apertures can ensure accurate assembly of parts, improve the performance and reliability of the entire equipment, and meet the needs of the automotive, shipbuilding, aerospace and other industries for high-precision hole parts.
EDM
EDM is a process that uses the high temperature generated by the pulse discharge between the electrode and the workpiece to corrode the workpiece material. For example, if we process an injection mold with a complex internal structure, the discharge gap between the electrode and the workpiece can be controlled at 0.02-0.1 mm, and the discharge pulse frequency is 10-100 kHz. By precisely controlling the discharge energy and position, the workpiece material is gradually eroded to produce a fine structure with a depth of 10-50 mm and a minimum inner corner radius of 0.5-2 mm, meeting the high-precision requirements of the mold.
I found that some high-hardness, high-toughness materials, or parts with complex internal shapes are difficult to complete using traditional processing methods , such as the cooling channel mold of aircraft engine blades. However, EDM can accurately manufacture these complex structures without being limited by the hardness of the material, meeting the needs of high-tech industries such as aerospace and electronics for complex and precise molds.
Laser Cutting And Processing
Laser cutting uses a high-energy-density laser beam to rapidly melt or vaporize materials to achieve cutting and drilling. For example, in one of my projects, we needed to cut a 3 mm thick stainless steel sheet. The laser power can be set at 1000-3000 watts, and the cutting speed can reach 2-5 m/min. It can cut a narrow slit with a width of 0.1-0.3 mm, with an edge verticality within ±0.1 mm and a surface roughness of Ra3.2-Ra6.3 microns. At the same time, the path of the laser beam can be controlled by programming to cut complex graphics and process tiny holes.
If we have a large demand for cutting and fine drilling of thin plate materials, we can choose laser processing. Laser processing can complete these operations quickly and accurately, with the advantages of high processing accuracy, small heat-affected zone, and no mechanical stress. It can ensure the smoothness and burr-free of the processed edge, and improve the appearance and quality of the product. For example, in the manufacture of metal shells for smartphones, laser processing can achieve complex shape cutting and tiny hole processing, meeting the lightweight and personalized design requirements of the product.
Classification By Material
| Material Category | Material Name | Hardness And Properties | CNC Machining Conditions | Application Areas | Processing Example | Key Parameters |
| Metal Materials | Aluminium-Legierung | Relatively low hardness and low density, suitable for aerospace and other fields | Cutting speed: 1000-2000 m/min, feed rate: 0.2-0.5 mm/tooth | Aerospace, Automotive, Consumer Electronics | Processing of aluminum alloy ribs for aircraft wings, ensuring rib thickness tolerance ±0.1 mm and contour accuracy ±0.05 mm | Density: 2.7-2.8g/cm³, Hardness: Low |
| Rostfreier Stahl | High toughness and good corrosion resistance | Cutting speed: 100-300 m/min, feed rate: 0.1-0.3 mm/rev | Medical equipment, food processing, machinery manufacturing | Processing stainless steel shaft parts, ensuring surface roughness Ra0.8 – Ra1.6 microns, cylindricality ±0.005 mm | Hardness: high, corrosion-resistant, high surface quality requirements | |
| Titan-Legierung | High strength, high temperature resistance, corrosion resistance, suitable for aircraft engine parts | Cutting speed: 50-150 m/min, feed rate: 0.05-0.2 mm/tooth | Aerospace, high-end sporting goods | Processing of aircraft engine blades, precision requirements: surface accuracy ±0.05 mm, surface roughness Ra0.4 – Ra0.8 microns | Strength: 800-1000 MPa, high temperature resistance (400-600℃) | |
| Stahl | High strength, low cost, widely used in construction and manufacturing | Cutting speed: 500-1000 mm/min, drilling accuracy: ±1 mm, bevel angle: ±2° | Construction, machinery manufacturing, energy | Processing steel beams for construction, ensuring the accuracy of connection holes and end grooves, reducing construction costs and improving construction efficiency | Yield strength: 200-500 MPa, high cutting accuracy required | |
| Plastic Materials | Thermoplastics | Easy to reshape, widely used in large-scale production | Cutting speed: 800-1500 m/min, feed rate: 0.1-0.3 mm/tooth | Toys, consumer electronics, medical devices | Processing plastic toys, precision requirements: dimensional accuracy ± 0.2 mm, good surface quality | Good processability, low cost, suitable for large-scale production |
| Thermosetting plastics | High hardness after curing, suitable for electrical housing and high temperature environment | Grinding depth: 0.05-0.2 mm, surface roughness Ra0.8 – Ra1.6 μm, EDM | Electrical appliances, automobiles, electronic equipment | Processing electrical socket shells to ensure surface flatness and hole accuracy to avoid electrical short circuit risks | High hardness, heat resistance, good insulation performance | |
| Engineering Plastics | Good mechanical properties and weather resistance, suitable for high performance requirements | Cutting speed: 500-1000 m/min, feed rate: 0.1-0.3 mm/tooth | Automobiles, home appliances, medical devices | Processing of automobile dashboards, precision requirements: curvature accuracy ±0.05 mm, surface roughness Ra0.8 – Ra1.6 microns | Strong weather resistance, excellent appearance quality, suitable for complex environments | |
| Composite Materials | Carbon fiber composites | High strength and light weight, suitable for applications requiring high strength | Cutting speed: 100-300 m/min, feed rate: 0.05-0.2 mm/tooth | Wind power generation, aerospace, automobile manufacturing | Processing wind turbine blades, precision requirements: airfoil profile accuracy ±0.05 mm, surface roughness Ra0.8 – Ra1.6 microns | Strength: 3000-5000 MPa, light weight, strong wear resistance |
| Glass fiber composite materials | High strength, good water resistance and corrosion resistance, suitable for shipbuilding and shipbuilding | Cutting speed: 1-3 meters/minute, grinding accuracy: Ra1.6 – Ra3.2 micron | shipbuilding, marine engineering | Processing, cutting and grinding of ship hulls to ensure the dimensional accuracy and surface quality of ship hull components and reduce manufacturing costs | Corrosion-resistant, water-resistant, relatively low cost | |
| hybrid composites | Combines the advantages of different materials to optimize performance | CNC winding and molding process, accuracy: ±0.5 mm, pressure: 5-10 MPa | Wind power, clean energy, aerospace | Processing of wind turbine blade girders to ensure material density and uniformity, improve structural strength, and meet design requirements | Comprehensive performance optimization, high strength, suitable for high performance requirements |
Salient Characteristics Of CNC Machined Parts
CNC machining allows me to truly experience the precision and efficiency of manufacturing. It has become the core technology of modern manufacturing with its high precision, consistency and design flexibility. Compared with traditional machining methods, it can not only achieve a machining accuracy of ±0.01mm, but also greatly improve production efficiency through high automation. It also does not require mold investment, which reduces costs while ensuring design freedom and production adaptability .
High Accuracy And Consistency
CNC machining can achieve extremely high precision through precise programming and stable machine tool movement. The tolerance can be controlled within ±0.01mm, and it can ensure the dimensional consistency of mass-produced parts, reduce our scrap rate, and improve product quality stability, which is difficult to achieve with traditional machining methods.
Gestaltung Freedom
Because CNC machining is freed from the limitations of traditional machining on complex shapes, it can realize the design of almost any shape and can produce parts with complex internal structures and curved surfaces, providing broad space for innovative product design and meeting the needs of modern industry for personalized, high-performance products.
Improvement Of Processing Efficiency
CNC machine tools have a high degree of automation and can work continuously, reducing the time for manual tool change, adjustment, etc. For example, if we want to process a complex mechanical part, traditional processing may take several hours, while CNC processing only takes tens of minutes, which greatly shortens the production cycle and improves production efficiency.
Schnelles Prototyping And Small Batch Production
In the product development stage, CNC machining can quickly transform the design into a physical prototype, which is convenient for design verification and improvement. At the same time, for small batch customized production, there is no need for a large amount of mold investment, the cost advantage is obvious, and it can quickly respond to the diverse needs of the market and reduce the risk of our product development .
Wide Range Of Applications For CNC Machined Parts
CNC machined parts have high precision and strong adaptability and have been widely used in many industries. From aerospace to medical devices, it not only meets the requirements of precision and complexity in various industries, but also effectively improves production efficiency and product reliability , providing key support behind our projects .
Luft- und Raumfahrt
In the aerospace field, CNC machining is widely used to manufacture key components such as aircraft engine parts and fuselage structural parts. These parts not only require us to have highly precise machining, but also must be able to withstand the harsh flight environment. Through CNC machining, the high quality and high reliability of each component are ensured, thus ensuring flight safety and performance.
Automotive Manufacturing
The automotive manufacturing industry has extremely high requirements for the precision and reliability of parts. CNC machining plays a vital role in the production of key parts such as engine blocks and transmission gears. Through precise machining technology, CNC not only improves the performance of the car, but also enhances its durability and stability, ensuring driving safety.
Electronic Equipment Field
CNC machining is also indispensable in the field of electronic equipment, especially when we manufacture metal casings and internal precision parts for mobile phones, computers and other products. As consumers’ demand for thin and delicate products continues to increase, CNC machining technology helps these products achieve high precision and excellent appearance quality, meeting the high requirements of the market.
Medical device Industry
In the medical device industry, CNC machining is essential for the manufacture of high-precision parts such as artificial joints and surgical instruments. These parts not only require extremely high machining accuracy, but also must meet strict quality standards to ensure the safety and health of patients. CNC technology ensures the precise machining of each medical device part, providing a solid foundation for the advancement of the medical industry.
FAQs
What Is The Maximum Size Of A CNC Machined Part?
Of CNC machined parts depends on the specifications of our machine tools . Common machining center worktable sizes can reach 2m×4m, and large parts within this range can be processed, such as large molds, aviation structural parts, etc. However, extra-large parts may require specially customized machine tools, which are more expensive and difficult to process.
What Are Some Examples Of CNC Machined Parts?
For example , the complex curved surfaces and high precision requirements of the turbine blades of aircraft engines require CNC processing of the metal frame of the mobile phone to achieve exquisite appearance and precise assembly. The crankshaft of the automobile engine also requires CNC turning and milling to ensure its high precision and high performance.
How To Choose CNC Machined Parts?
We need to consider factors such as the precision requirements of the parts, the complexity of the shape, the material characteristics, and the batch size. For parts with high precision, complex shapes and small batches, five-axis linkage is suitable, while CNC machining centers for large batches of simple parts can use special machine tools to balance processing quality, efficiency and cost.
What Are The Advantages Of CNC Machined Parts?
Advantages include high precision, high consistency, large design freedom, high processing efficiency, rapid prototyping and small batch production, etc., which can help us improve product quality, shorten R&D cycle, reduce costs, meet the modern manufacturing industry’s demand for high-quality and diversified products, and enhance the company’s market competitiveness.
What Are 3 Tips Foder Choosing The Right Material For CNC Parts?
First of all, we need to consider the use environment and performance requirements of the parts. For example, titanium alloy should be selected for high temperature resistance. Secondly, we should pay attention to the processing performance of the material, such as aluminum alloy is easy to cut. Finally, considering the cost factor, we should choose lower-cost materials while meeting the performance requirements. For example, steel should be selected instead of precious metals for ordinary structural parts.
What Materials Are Best Suited For CNC Machines?
I think there is no absolutely most suitable material. Different materials are suitable for different scenarios. Among metals, aluminum alloy has good processability and is widely used. Among plastics, engineering plastics have excellent performance. Composite materials such as carbon fiber composite materials have advantages in high-end fields. You need to choose according to the specific parts requirements.
Conschluss
Through this article, we have a comprehensive understanding of the core position of CNC machining parts in modern manufacturing. CNC machining technology provides strong support for the development of various industries with its high precision, high efficiency and high flexibility. With the continuous advancement of technology, CNC machining will play a greater role in new materials, new processes and intelligent manufacturing, and promote the global manufacturing industry to move towards higher standards.