Guide of CNC Manufacturing Custom Parts

CNC manufacturing is used for producing custom machined parts by automated process. Standard CNC machines include 3-axis, 4-axis, and 5-axis milling machines, lathes, and routers. Generally it is suitable for customization, rapid prototyping and production parts.
At Sungplastic, we delve into CNC manufacturing and advanced CNC machining centre to create custom parts and provide precision-machined parts in low or large quantities for satisfying diverse demands, with the assistance of our fast services, advanced equipment and quality workmanship.

CNC Manufacturing

What is CNC Manufacturing?

CNC manufacturing, which stands for Computer Numerical Control manufacturing, is a highly automated and precise manufacturing process used to create custom parts and components from various materials. It relies on computer-controlled machines and tools to accurately shape and form raw materials into finished products. CNC manufacturing offers several key advantages, including precision, repeatability, and the ability to produce complex and customized parts. CNC manufacturing is ideal for customization and small-batch production to meet diverse market demands.

Types of CNC Machining Centers

CNC machining centers are sophisticated manufacturing machines that use computer numerical control (CNC) technology to automate and control various machining operations. These centers are integral to CNC manufacturing as they are capable of performing a wide range of tasks with high precision and repeatability. The primary role of CNC machining centers is to take digital design data (typically in the form of CAD/CAM files) and transform it into physical, custom-made parts and components by accurately removing material from workpieces.

    • CNC Milling Machines
      CNC milling machines are used for cutting and shaping solid materials. They employ rotating cutting tools to remove material from a workpiece, resulting in 3D shapes and features. This versatility makes them suitable for producing parts with intricate geometries.
    • CNC Turning Machines
      CNC turning machines, also known as CNC lathes, are designed for machining cylindrical or rotational parts. They rotate the workpiece while cutting tools move parallel to the axis, allowing for the creation of parts like shafts, bolts, and bushings.
    • CNC Drilling Machines
      CNC drilling machines are specialized for creating precise holes in workpieces. They are commonly used in industries where hole placement and size accuracy are paramount, such as aerospace and automotive.
    • Other Specialized CNC Machines
      In addition to milling, turning, and drilling machines, there are various other specialized CNC machining centers designed for specific tasks, including grinding, electrical discharge machining (EDM), and laser cutting, among others.

Advantages of CNC Machining

    • Precision and Accuracy:
      CNC machining centers offer unparalleled precision and accuracy, allowing for the production of parts with tight tolerances.
    • Efficiency:
      They are highly efficient, with the ability to run continuously and produce parts rapidly, minimizing lead times.
    • Flexibility:
      CNC machining centers can handle various materials and accommodate a wide range of part geometries.
    • Repeatability:
      They ensure consistent quality and repeatability, making them ideal for mass production.
    • Automation:
      CNC machining centers reduce the need for manual labor, increasing productivity and reducing the risk of errors.

The prototype parts we make are finally assembled together to get the perfect prototype. It is the best for customers to test appearance and assembly.
A perfect prototype will greatly promote the smooth processing of injection molds and mass injection molding manufacturing.

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Types of CNC Manufacturing Operations

CNC (Computer Numerical Control) manufacturing encompasses a variety of operations that use computer-controlled machines to produce custom parts and components with precision and consistency. Here’s a brief introduction to some common types of CNC manufacturing operations:

    • CNC Machining
      CNC machining is a versatile operation that includes processes like CNC milling and CNC turning. It involves the use of rotary cutting tools to remove material from a workpiece, creating complex shapes, holes, and surfaces. CNC machining is widely used across industries for its accuracy and versatility.
    • CNC Routing
      CNC routing uses computer-controlled routers to cut, trim, and shape materials like wood, plastics, and composites. It’s commonly used in woodworking, cabinetry, and sign-making.
    • CNC Laser Cutting
      CNC laser cutting employs high-powered lasers to precisely cut or engrave various materials, including metals, plastics, and ceramics. It’s favored for its speed and precision in producing intricate designs.
    • CNC Plasma Cutting
      CNC plasma cutting uses a high-temperature plasma arc to cut through electrically conductive materials, primarily metals. It’s often used in metal fabrication for cutting intricate shapes and profiles.
    • CNC Waterjet Cutting
      CNC waterjet cutting utilizes a high-pressure stream of water mixed with abrasive particles to cut through a wide range of materials, including metal, glass, and stone. It’s valued for its versatility and minimal heat generation.
    • CNC Electrical Discharge Machining (EDM)
      EDM operations, including wire EDM and sinker EDM, use electrical discharges to remove material from a workpiece. It’s suitable for producing intricate, high-precision parts, particularly in tool and die making.
    • CNC Grinding
      CNC grinding employs abrasive wheels to precisely grind and finish surfaces. It’s used to achieve tight tolerances and surface quality in parts such as bearings and hardened steel components.
    • CNC 3D Printing
      Although not traditional machining, CNC 3D printing, also known as additive manufacturing, builds parts layer by layer using computer-controlled processes. It’s ideal for creating complex and customized 3D objects.
    • CNC Bending and Forming
      CNC press brakes and other equipments are used to bend and shape sheet metal and other materials into desired forms. This operation is vital in sheet metal fabrication.
    • CNC Swiss Machining
      CNC Swiss machining combines turning and milling capabilities in a single machine. It’s suitable for high-precision, small-diameter parts, often used in the medical and aerospace industries.
    • CNC Wire Forming
      CNC wire forming machines bend and shape wire materials into custom profiles and designs. It’s used in various applications, including springs and wire-based components.

CNC Manufacturing Materials

CNC (Computer Numerical Control) manufacturing encompasses a wide range of materials to create custom parts and components with precision and accuracy. The choice of material depends on specific requirements, including mechanical properties, environmental conditions, and application. Here’s an introduction to some common materials used in CNC manufacturing.


    • Aluminum
      Lightweight, corrosion-resistant, and versatile, aluminum is widely used in aerospace, automotive, and consumer electronics.
    • Steel
      Known for its strength and durability, steel is used in various forms, including carbon steel and stainless steel.
    • Stainless Steel
      Offers excellent corrosion resistance and is ideal for applications requiring hygiene and longevity.
    • Brass
      Valued for its aesthetic appeal and corrosion resistance, brass is often used in decorative and electrical components.
    • Copper
      A good conductor of electricity and heat, copper is used in electrical components and heat exchangers.
    • Titanium
      Known for its high strength-to-weight ratio and corrosion resistance, titanium is used in aerospace and medical applications.
    • Nickel Alloys
      Nickel alloys offer high-temperature and corrosion resistance, making them suitable for extreme environments.


    • Acrylic (PMMA)
      Transparent and weather-resistant, acrylic is used in signage, displays, and lighting fixtures.
    • Delrin (Acetal)
      High-strength and low-friction, Delrin is ideal for engineering and industrial applications.
    • Nylon (PA)
      Durable and versatile, nylon is used for gears, bearings, and industrial components.
    • Polyethylene (PE)
      Comes in various forms, including high-density polyethylene (HDPE), used for conveyor guides and wear strips.
    • Polycarbonate (PC)
      Known for its strength and impact resistance, polycarbonate is used in safety goggles and electronic housings.
    • Polypropylene (PP)
      Offers chemical resistance and low moisture absorption, used in medical devices and packaging.
    • Polyurethane (PU)
      Flexible and abrasion-resistant, polyurethane is used for seals, gaskets, and wheels.

Other Materials

    • Composites
      Materials like carbon fiber-reinforced composites are used in aerospace, automotive, and sports equipment.
    • Rubber
      Rubber components, such as gaskets and seals, are manufactured using CNC machining.

CNC Manufacturing Processes

There are several aspects to consider in CNC manufacturing. When we understand these and implement the common rules, we can produce the perfect CNC parts.

CNC Programming

CNC programming is the foundation of CNC manufacturing, as it involves creating the set of instructions that guide the CNC machine’s movements and operations. This programming process is highly critical and requires expertise in computer-aided design (CAD) and computer-aided manufacturing (CAM) software.

    • CAD/CAM Software
      CNC programmers use CAD software to design the part and create a digital model. CAM software then translates the CAD model into CNC code, such as G-codes and M-codes, which the machine understands.
    • Toolpath Generation
      CAM software generates toolpaths based on the part’s geometry, specifying the exact path the cutting tool will follow. The programmer may optimize toolpaths to minimize cycle times and maximize efficiency.
    • Tool Selection
      Programmers choose appropriate cutting tools, taking into account factors like material, geometry, and the desired surface finish. Tool selection significantly affects the machining process’s success.
    • Speeds and Feeds
      CNC programmers set parameters for cutting speeds (surface speed of the tool) and feeds (rate at which the tool advances). These parameters influence tool life, material removal rates, and surface finish.
    • Tool Changes
      Tool change sequences are programmed to ensure the machine switches tools efficiently when multiple tools are needed for a single part.
    • Safety Considerations
      CNC programmers must consider safety aspects, such as tool clearances, to prevent tool collisions, machine damage, and workpiece defects.
    • Simulation and Verification
      Before running the CNC program on the actual machine, programmers often use simulation software to verify that the toolpaths are correct and there are no errors in the code.

Material Selection for CNC Manufacturing

Choosing the right material for CNC manufacturing is crucial because it directly impacts the part’s performance, durability, and cost-effectiveness.

    • Material Properties
      Engineers and designers consider the mechanical, thermal, electrical, and chemical properties required for the specific application. Materials must meet these requirements.
    • Cost and Availability
      Material cost and availability play a significant role in selecting materials. High-performance alloys may be expensive, while common metals like aluminum and steel are readily available and cost-effective.
    • Machinability
      The ease with which a material can be machined is a key factor. Some materials are more difficult to machine due to hardness or abrasiveness, which can affect tool life and machining time.
    • Surface Finish
      Certain materials, like plastics and composites, may require additional attention to achieve the desired surface finish. This affects post-machining processes.
    • Environmental Considerations
      In some industries, materials must meet specific environmental and regulatory requirements, such as RoHS compliance for electronics.

CNC Tooling and Cutting Processes

CNC tooling and cutting processes are central to achieving precision and accuracy in CNC machining.

    • Cutting Tools
      Selecting the appropriate cutting tools is crucial. Factors such as material type, cutting speed, and feed rate influence tool choice. Common tools include end mills, drills, inserts, and reamers.
    • Tool Geometry
      The geometry of cutting tools, including angles, flutes, and coatings, is optimized for specific materials and cutting operations.
    • Coolant and Lubrication
      Coolants or lubricants may be used to dissipate heat and reduce friction during cutting, improving tool life and surface finish.
    • Cutting Parameters
      CNC operators set parameters like spindle speed, feed rate, and depth of cut based on tooling and material considerations.
    • Toolpath Optimization
      Toolpaths are designed to optimize material removal rates while minimizing tool wear and machining time. Strategies include contouring, pocketing, and adaptive clearing.

Quality Control and Inspection in CNC Manufacturing

Quality control and inspection are critical steps to ensure that CNC machined parts meet specified tolerances, dimensions, and quality standards.

    • In-Process Inspection
      During machining, operators may use measurement tools such as micrometers, calipers, and gauges to check critical dimensions and tolerances.
    • Coordinate Measuring Machines (CMMs)
      CMMs are precise measuring devices used to inspect complex parts and verify their dimensional accuracy.
    • Statistical Process Control (SPC)
      SPC techniques, including statistical analysis and control charts, are employed to monitor and control the machining process’s consistency and quality.
    • First Article Inspection (FAI)
      FAI is conducted on the initial part to verify that it meets all design requirements. It’s a crucial step in validating the machining process.
    • Non-Destructive Testing (NDT)
      NDT methods like ultrasonic testing and dye penetrant inspection may be used to detect defects without damaging the part.
    • Surface Roughness Measurement
      Surface finish is assessed using instruments such as profilometers to ensure it meets specifications.

Finishing and Surface Treatment in CNC Manufacturing

Surface finishing and treatment processes are applied to CNC machined parts to enhance their appearance, protect against corrosion, and meet specific requirements.

    • Anodizing
      Anodizing is an electrochemical process that forms a protective oxide layer on aluminum surfaces, improving corrosion resistance and providing color options.
    • Electroplating
      Electroplating involves depositing a layer of metal, such as chrome or nickel, on the surface to enhance aesthetics and corrosion resistance.
    • Painting and Powder Coating
      Painting and powder coating are used to provide parts with protective finishes and various colors.
    • Polishing and Buffing
      Polishing and buffing processes create smooth and reflective surfaces, improving aesthetics.
    • Passivation
      Passivation removes surface contaminants from stainless steel, enhancing its corrosion resistance.
    • Laser Marking/Engraving
      Laser marking and engraving are used for branding, identification, and customization of parts.
    • Heat Treatment
      Heat treatment processes like annealing, hardening, and tempering can be applied to improve mechanical properties.
    • Surface Grinding
      Surface grinding is a precision machining process used to achieve tight tolerances and improved surface flatness and smoothness.
    • Bead Blasting
      Bead blasting creates a uniform and matte finish on surfaces, often used to remove burrs and provide a textured appearance.

Applications of CNC Manufacturing

CNC manufacturing has a wide range of applications across various industries due to its precision, versatility, and efficiency. Here, we delve into the specific applications of CNC manufacturing in key sectors.

Aerospace and Defense Industry

CNC manufacturing is critical in aerospace for producing complex and high-precision components like aircraft engine parts, landing gear, and structural elements.
Defense applications involve the production of military-grade components, such as weapon systems, armored vehicle parts, and aerospace components used in defense technology.
CNC manufacturing ensures parts meet stringent quality and safety standards, contributing to the reliability of aircraft and defense systems.

Automotive Industry

CNC manufacturing produces engine components, transmission parts, brake components, and chassis parts.
It enables the creation of intricate molds and dies for automotive body panels, ensuring precision in mass production.
CNC manufacturing allows for the customization of performance parts and prototypes for research and development.

Medical and Healthcare Sector

CNC machining is vital for manufacturing medical devices and equipment, such as surgical instruments, orthopedic implants, and dental prosthetics.
CNC manufacturing also facilitates the creation of custom prosthetics and patient-specific implants through computer-aided design (CAD) and computer-aided manufacturing (CAM) processes.

Electronics and Semiconductor Manufacturing

CNC manufacturing is used in the electronics industry to produce components like circuit boards, connectors, and heat sinks with high precision.
Semiconductor manufacturing relies on CNC machines for precision machining of silicon wafers, ensuring the miniaturization and functionality of electronic devices.
CNC wire and sinker EDM (Electrical Discharge Machining) are employed for micro-machining and intricate features in electronic components.

Precision Engineering and Toolmaking

CNC manufacturing is ideal for precision engineering, creating tools, dies, and molds.
It enables the production of precision gauges, measuring instruments, and optical components with sub-micron accuracy.
Tool and die makers rely on CNC manufacturing to fabricate complex molds for plastic injection molding and stamping operations.

Custom and Prototyping Services

CNC manufacturingoffers rapid prototyping capabilities, allowing engineers and designers to test and iterate on product designs.
Custom CNC manufacturing services are especially beneficial for small-batch or one-off production runs of specialized components quickly.

Other Industrial and Consumer Goods Sectors

CNC machining finds applications in furniture manufacturing, jewelry production, and architectural metalwork.
In the consumer goods sector, CNC manufacturing is used for crafting custom parts for motorcycles, bicycles, and sporting equipment.
It contributes to the production of intricate and artistic components in sculptures, artworks, and ornamental designs.

Advanced CNC Manufacturing Centre–Sungplastic

Sungplastic is a Chinese manufacturer with rich experience in CNC manufacturing. According to the customized processing requirements of different products, we will flexibly adjust the manufacturing process to achieve high-quality, high-efficiency, and more economical production.

    • Programming:
      Interpreting drawings, CAD/CAM files, or blueprints.
      Presenting completed work to clients and making changes as necessary.
    • Skilled Technicians:
      Assembling, putting into operation, and taking apart manual, automatic, and computer numerically controlled (CNC) machine tools.
      Machine parts that are turned, milled, drilled, shaped, and ground to specifications.
      Inspecting, measuring, and testing finished products for flaws.
      Surface finishes on parts or products.
      Cutting tool and workpiece alignment, security, and adjustment.
    • Wide Range of Materials:
      Including metals, plastics, composites and custom materials for CNC manufacturing.

At the same time, we provide full services: rapid prototyping, rapid manufacturing, mold making, injection molding, CNC machining and metal stamping. You can choose various plastics, silicone rubber or metals for your products, and we will give the best material suggestion. Whether it is mass production or small batch manufacturing, Sungplastic is always committed to providing assured, efficient and more economical one-stop processing services for your projects.

Contact us for a free quote and project review.

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