In modern manufacturing, CNC (Computer Numerical Control) processed parts play a crucial role. Whether in automated equipment, automotive manufacturing, or medical device industries, high-precision and high-quality custom CNC processed parts are indispensable. This article will comprehensively introduce the types, advantages, and design considerations of CNC processed parts, helping you gain a deeper understanding of this key manufacturing process.
What are Machined Parts?
Machined parts refer to those manufactured through the machining process (machining). The core of this process lies in using machine tools (such as CNC milling, CNC turning, milling, drilling, grinding, etc.) and cutting tools, in a physical cutting manner, to remove excess material (producing chips) from the pre-prepared solid raw materials (such as metal rods, plates, cast and forged blanks) to precisely shape and form, ultimately obtaining the specific shape, size and surface quality of the parts as required by the design.
The main advantage of this process lies in its ability to achieve high precision and excellent surface finish, making it a crucial method for manufacturing complex and precise parts. Machined parts are widely used in fields with strict requirements for dimensions, shapes, fits, and surfaces, such as automotive engine components, precision parts for automated equipment, core components of food packaging machinery, medical devices, and various tooling and molds. They are an indispensable manufacturing foundation in modern manufacturing.
It is one of the most widely used, fundamental and crucial processes in modern manufacturing, which is essential for achieving high-precision part production. The popularization of CNC (Computer Numerical Control) technology has significantly enhanced the automation level, precision and the ability to process complex shapes in machining.
Types of parts for numerical control processing
1.Shaft-type Parts
Shaft-type parts are one of the common types in CNC machining. Their main feature is that the length is greater than the diameter. They are usually used to transmit torque, support transmission components, etc. For example, the crankshaft in an automobile engine converts the reciprocating motion of the piston into rotational motion and has extremely high precision requirements. Shaft-type parts are generally ensured to have dimensional accuracy and surface roughness through CNC machining processes such as turning and grinding.
2.Cylindrical Parts
These parts usually have diameters much larger than their thicknesses, such as various gears, flanges, etc. Gears play a role in mechanical transmission systems by transmitting power and changing rotational speed. Through CNC milling or gear rolling processing, the tooth shapes can be precisely manufactured. Flanges are often used for connecting pipes or equipment. CNC machining can ensure the positional accuracy and flatness of the bolt holes.
3.Box-type Parts
Box-type parts have a relatively complex structure, with internal cavities and multiple planes. They are commonly found in the headstock of machine tools and the transmission bodies of automobiles. Due to the need to install various transmission components inside, strict requirements are imposed on the positional accuracy of each hole system, the accuracy of hole diameters, and the flatness. CNC machining centers can achieve efficient and precise processing of box-type parts through multi-axis linkage.
4.Complex Curved Surface Parts
These parts have surfaces that are complex spatial curves, such as blades of aircraft engines and mold cavities. The processing of these curved surfaces is very difficult, and traditional processing methods cannot meet the accuracy requirements. CNC machining, with its ability to precisely control the movement trajectory of the cutting tool, can achieve high-precision processing of complex curved surfaces through 3-axis, 4-axis, and 5-axis linkage processing technologies, ensuring the accuracy dimensions of custom parts.
The Advantages Of Machined Parts
The non-standard customized parts processed by numerical control have more advantages compared to those produced by other manufacturing methods. The following section will delve into some of the main benefits of this.
1.No MOQ
One of the significant advantages of CNC machining parts is their flexibility in terms of order quantity, as there is no requirement for a minimum order quantity (MOQ). No matter how unique and complex the parts you need are, they can be customized as per your requirements, fully meeting your diverse and personalized needs. It helps you solve the customization problems of small batches and special specifications of parts, and supports the smooth progress of your projects.
2.High Precision
CNC machining can achieve extremely high dimensional accuracy, typically controlled within ±0.01mm or even higher. This is beyond the reach of traditional processing methods. High-precision parts can enhance the overall performance and reliability of products, and reduce assembly problems and failures caused by insufficient part accuracy.
3.High Production Efficiency
CNC processing equipment can perform automated continuous processing, reducing auxiliary time such as manual tool changing and measurement. At the same time, by optimizing the processing program, the cutting speed and feed rate can be increased, significantly shortening the processing time for individual parts. In mass production, the high efficiency of CNC processing is more evident, enabling rapid response to market demands.
4.High Flexibility
By simply modifying the CNC processing program, different shapes and sizes of parts can be easily processed without the need to frequently replace molds or fixtures as in traditional processing. This makes CNC processing particularly suitable for multi-variety, small-batch production models, enabling rapid response to market changes and reducing production costs and inventory pressure for enterprises.
5.Complex Shape Processing Capability
CNC machining can complete the processing of complex curved surfaces and irregular structures. This provides strong support for innovative product design, allowing engineers to break through the limitations of traditional processing and design products with more functionality and aesthetics, driving technological progress in various industries.
6.Good Quality Stability
Due to the program control in the CNC processing process, the influence of human factors on processing quality is reduced, and the quality consistency of the same batch of parts is high. This helps to improve the overall quality stability of the product, reduce scrap rates, and enhance the market competitiveness of the enterprise.
Materials Used for CNC Machining Parts
With its advantages of high precision, high efficiency and high automation, numerical control processing has become a key technology for manufacturing complex and precise parts. As the foundation of numerical control processing, the properties of the materials directly determine the quality, function and production cost of the parts. Understanding various materials used in numerical control processing is crucial for optimizing the processing techniques and improving product quality.
Steel
1.Carbon Steel
Affordable in price and easy to process, it is widely used in mechanical manufacturing. Low-carbon steel has a carbon content lower than 0.25%, with good plasticity and weldability, and is often used to manufacture standard parts such as nuts and bolts. Medium-carbon steel has a carbon content of 0.25% - 0.60%, with excellent comprehensive mechanical properties, suitable for manufacturing parts such as gears and shafts that bear certain loads. High-carbon steel has a carbon content higher than 0.60%, and after quenching and tempering treatment, it has excellent hardness and wear resistance, often used to manufacture tools and molds.
2.Alloy Steel
Based on carbon steel, alloy elements such as chromium, nickel, and molybdenum are added, significantly improving its performance. Chromium steel has good corrosion resistance and oxidation resistance, often used to manufacture parts for chemical equipment. Nickel-chromium steel has superior comprehensive mechanical properties, widely used in aerospace, automotive manufacturing, and other fields.
Aluminum
Aluminum has a low density, excellent electrical conductivity and thermal conductivity, and outstanding processing performance. Pure aluminum has relatively low strength. Aluminum alloys, by adding elements such as copper, magnesium, and zinc, significantly increase strength and hardness. 6061 aluminum alloy has moderate strength, good corrosion resistance and processing performance, and is commonly used to manufacture automotive parts and electronic product casings. 7075 aluminum alloy has high strength, approaching that of steel, and is often used in the aerospace field, such as manufacturing aircraft beams and landing gear.
Aldary
1.Pure Copper
Also known as red copper, it has the highest conductivity and thermal conductivity among metals, and excellent plasticity. However, its strength and hardness are relatively low. It is commonly used to manufacture wires, cables, and heat-conducting components.
2.Yellow Copper
It is mainly composed of zinc as the alloying element and has good machinability, corrosion resistance, and decorative properties. It is often used to manufacture valves, pipe fittings, and handicrafts.
3.Bronze
It is mainly composed of elements such as tin, aluminum, and beryllium. There are various types. Tin bronze is wear-resistant and corrosion-resistant, and is often used to manufacture bearings and gears. Beryllium bronze has good elasticity and high strength, and is often used to manufacture elastic components and explosion-proof tools.
Titanium Alloy
Titanium has a low density, high strength and excellent corrosion resistance, and is widely used in the aerospace and medical device industries. Pure titanium has good plasticity but relatively low strength. Titanium alloys add elements such as aluminum and vanadium, which significantly enhance strength and heat resistance. For example, the Ti - 6Al - 4V alloy has excellent comprehensive performance and is often used to manufacture aircraft engine blades, fuselage components, as well as artificial joints and dental implants.
Engineering Plastics
1.Polyamide (PA)
Also known as nylon, it has excellent wear resistance, self-lubrication properties and mechanical strength, and is widely used in the manufacturing of gears, bearings, and sealing rings.
2.Polycarbonate (PC)
It has high strength, high transparency and impact resistance, and is often used in the production of optical lenses and electronic product casings.
3.Polyoxymethylene (POM)
It has excellent wear resistance, fatigue resistance and dimensional stability, and is commonly used in the manufacturing of precision mechanical parts and automotive components.
Composite Material
1.Fiber-reinforced composite materials
These are composed of fibers (such as glass fibers, carbon fibers) as the reinforcing elements and resin as the matrix. Glass fiber-reinforced composite materials have low cost and high strength, and are commonly used in manufacturing car bodies and yachts. Carbon fiber-reinforced composite materials have high strength, low density, and high temperature resistance, and are widely used in aerospace and high-end sports equipment.
2.Ceramic matrix composite materials
These are made with ceramics as the matrix and add fibers as the reinforcing phase. They possess high strength, high hardness, high temperature resistance, and wear resistance, and are often used in manufacturing cutting tools and engine hot-end components.
Key points for designing parts using numerical control processing
1.Selecting Appropriate Materials
Based on the usage requirements and performance characteristics of the parts, choose the suitable materials. For example, for parts that bear high loads, high-strength metal materials should be selected; for parts that require lightweight, lightweight materials such as aluminum alloys and titanium alloys can be considered. At the same time, it is necessary to fully understand the cutting performance of the selected materials to formulate reasonable process parameters in the CNC machining process.
2.Simplifying the Part Structure
While meeting the functional requirements of the parts, try to simplify their structure. A complex structure not only increases the processing difficulty and cost, but also may make it difficult to ensure the processing accuracy. For example, avoid excessive deep holes, thin-walled structures, etc., as these structures are prone to deformation and vibration during the processing.
3.Considering Machining Processability
When designing the parts, fully consider the process characteristics of CNC machining. For example, reasonable settings of retraction grooves, process holes, etc., facilitate the movement of the tool and positioning and clamping during the processing. At the same time, ensure that there is sufficient machining allowance between the processing surfaces of the parts to avoid parts being scrapped due to insufficient allowance.
4.Standardized Dimension Annotation
Accurate and standardized dimension annotation is the foundation of CNC machining. Dimension annotation should comply with national standards, avoid closed dimension chains, and be easy for programming personnel to understand and calculate. Important dimensions should be directly annotated to ensure the control of processing accuracy.
5.Reasonable Tolerance Control
Based on the usage requirements of the parts, reasonably determine the tolerance range. Too small tolerances will increase the processing difficulty and cost, while too large tolerances may affect the assembly and usage performance of the parts. Therefore, while ensuring product quality, try to relax the tolerance requirements as much as possible to improve processing efficiency and reduce costs.
Da Hong Precision has over 9 years of experience in non-standard customized processing of parts. There is no minimum order quantity requirement. Whether you need customized parts for automation equipment, food machinery, automotive parts, or medical equipment and other projects, please feel free to contact us at any time!
Let's Make Something Extraordinary Together
At Dahong Precision, we are more than just a CNC machining supplier, we are your partner in precision manufacturing. Whether you need simple parts or highly complex parts, our 3, 4 and 5 axis CNC machining services deliver the quality and reliability you deserve. Contact us today to discuss your project and find out how we can help you achieve your goals.
