CNC Machining of Aerospace Parts : A Manufacturing Guide You Need to Learn
- CNC Machining of Aerospace Parts : A Manufacturing Guide You Need to Learn
- A brief introduction to CNC machining of aerospace parts
- The Importance of High-Precision CNC Parts in the Aerospace Field
- CNC machining processes commonly used in aerospace parts manufacturing
- Complete step-by-step process of CNC machining for manufacturing aerospace parts
- 1. Requirements review and technical feasibility analysis
- 2. Material selection and certification verification
- 3. Design for Manufacturability (DFM) Review
- 4. CNC machining process planning
- 5. CAM Programming
- 6. Preparation of cutting tools and fixtures
- 7. Verification of machine tool settings and first piece settings
- 8. First article processing (FAI sample)
- 9. First Article Inspection (FAI)
- 11. Process inspection and process monitoring
- 12. Secondary processing
- 13. Deburring and edge treatment
- 14. Heat treatment (if necessary)
- 15. Surface treatment and finishing
- 16. Final Dimensioning and Appearance Inspection
- 17. Non-destructive testing (NDT) (if required)
- 18. Documentation and traceability control
- 19. Cleaning and Maintenance
- 20. Packaging and Delivery
- Industry standards and regulations for CNC machining of aerospace parts
- Design considerations for aerospace components
- Design for Manufacturability (DFM) for CNC-manufactured parts in aerospace projects
- Common materials used in manufacturing custom aerospace CNC parts
- Common aerospace CNC-manufactured custom parts
- Advantages of CNC machining for the aerospace industry
- Future Development of CNC Manufacturing Technology for Aerospace Components
- Elimold’s CNC machining capabilities for aerospace precision parts
- in conclusion
- FAQ
CNC machining technology is crucial in the aerospace industry , primarily because it meets the industry’s requirements for parts that possess both precision and accuracy . Components manufactured using this automated technology ensure compliance with the highest safety and performance standards , as well as reliable operation under extreme conditions. As the industry continues to evolve, the demand for these precision-manufactured parts continues to surge, highlighting the vital role of CNC machining . This article will introduce the basic and key considerations for using CNC machining to manufacture aerospace components.
A brief introduction to CNC machining of aerospace parts
CNC machining for aerospace parts is primarily used to create precision parts for assembling and maintaining related equipment. The main process involves using advanced computer-controlled machine tools to manufacture precision parts that meet aerospace standards. These machine tools have tolerances down to ±0.005 mm, meeting stringent safety and performance standards. This process can machine complex shapes, precisely fitted, and highly reliable flight-critical components.
The aircraft parts that can be manufactured include bushings, hinges, clamps, and other custom parts, and all of these parts are made of high-strength materials that meet stringent standards. All of this is to ensure that these aircraft components operate properly without involving any form of danger.
The Importance of High-Precision CNC Parts in the Aerospace Field
Why does the aerospace industry require highly precise, custom-made CNC components? There are many reasons, but the main one is that all components used in the aerospace field must meet the stringent safety and performance standards of each country and industry. Even the slightest deviation in an aircraft can lead to catastrophic system failures and endanger the lives of passengers on board.
Therefore, when custom parts are required to meet standards, precise CNC machining is necessary so that the parts can be manufactured according to the drawings and industry standard specifications, thereby maintaining the structural stability and functionality of the components during aircraft operation.
Furthermore, the precise design of aerospace CNC components is essential for achieving the required aerodynamic characteristics, which directly impact fuel consumption and general flight performance. Therefore, cost management and sustainability are crucial for aerospace manufacturing companies. Manufacturers must employ improved CNC technology to ensure that every product meets the stringent standards of the aerospace industry.
CNC machining processes commonly used in aerospace parts manufacturing
Different aerospace applications require different machining processes. Based on our experience in manufacturing parts for the aerospace industry, the parts typically require the following CNC machining processes.
| CNC Machining Process | Brief Explanation |
| CNC Milling (3-Axis) | Linear multi-axis cutting used for planar surfaces, slots, and simple geometries with tight tolerances. |
| CNC Milling (4-Axis) | Adds rotary motion to enable machining on multiple faces without re-clamping, improving accuracy and efficiency. |
| CNC Milling (5-Axis) | Simultaneous movement of five axes enables complex contours, undercuts, and compound angles in a single setup. |
| CNC Turning | Rotational machining process for cylindrical or axisymmetric components with high dimensional accuracy. |
| CNC Turn-Mill (Mill-Turn) | Combines turning and milling in one setup, reducing handling errors and cycle time. |
| Swiss-Type CNC Machining | High-precision turning for small-diameter, long-slender parts using guide bushing support. |
| High-Speed Machining (HSM) | Uses high spindle speeds and feed rates to reduce cutting forces and improve surface quality. |
| Hard Machining | Machining of hardened metals (>45 HRC) as an alternative to grinding, maintaining dimensional stability. |
| Precision Drilling & Reaming | Produces high-accuracy holes with controlled diameter, roundness, and surface finish. |
| Thread Milling & Tapping | CNC-controlled thread generation for high-strength, repeatable threaded features. |
| EDM (Wire EDM) | Non-contact electrical discharge machining for intricate profiles in conductive materials. |
| EDM (Sinker EDM) | Uses shaped electrodes to create deep cavities or sharp internal corners. |
| Surface Grinding (CNC) | High-precision finishing process for flatness and surface finish control. |
| CNC Deburring & Edge Conditioning | Automated removal of burrs and edge sharpness to meet aerospace safety standards. |
Complete step-by-step process of CNC machining for manufacturing aerospace parts
When manufacturing aerospace components using CNC machining, several processes are involved to ensure accuracy, quality, and compliance with industry standards.
1. Requirements review and technical feasibility analysis
Review engineering drawings, specifications, material standards, tolerances, and regulatory requirements (such as AS9100 and customer specifications) to confirm their manufacturability, compliance, and risk factors.
2. Material selection and certification verification
Select aerospace-grade materials (such as aluminum alloys, titanium alloys, and nickel-based superalloys) and verify factory certificates (Material Test Reports, MTRs) to ensure full traceability and compliance.
3. Design for Manufacturability (DFM) Review
Evaluate part design to optimize geometry, tolerances, tool feed, and fixture strategies, thereby reducing costs, shortening machining cycles, and mitigating machining risks without compromising functionality.
4. CNC machining process planning
Based on the complexity of the parts and the material properties, determine the machining strategy, process sequence, cutting tools, fixtures, inspection points, and machine tool selection (three-axis, five-axis, or mill-turn machine tool).
5. CAM Programming
CAM software is used to generate toolpaths, define cutting parameters, simulate machining operations, and verify collision-free execution while maintaining dimensional accuracy.
6. Preparation of cutting tools and fixtures
Cutting tools, tool holders, custom fixtures, and workpiece clamping devices all need to be prepared, calibrated, and verified to ensure their rigidity, repeatability, and positional accuracy.
7. Verification of machine tool settings and first piece settings
Set up the CNC machine tool using the selected tools and fixtures, establish the workpiece coordinate system, and verify the settings to ensure correct alignment and reference.
8. First article processing (FAI sample)
Initial parts are machined under controlled conditions to validate machining strategies, toolpaths, and dimensional accuracy before proceeding to full-scale production.
9. First Article Inspection (FAI)
The first piece is inspected using a coordinate measuring machine (CMM) and precision gauges to confirm its conformity with drawing, tolerance, and geometric tolerance (GD&T) requirements. 10. CNC Machining
Parts are manufactured using approved processing procedures, and parameters are controlled to ensure consistency, repeatability, and surface integrity.
11. Process inspection and process monitoring
Inspect critical dimensions and features during processing to detect deviations early, ensure stable process control, and minimize scrap.
12. Secondary processing
Perform additional operations such as drilling, reaming, tapping, thread milling, or electrical discharge machining to complete complex features or hard-to-reach geometries.
13. Deburring and edge treatment
Remove burrs, sharp edges, and surface irregularities to meet aerospace safety, assembly, and fatigue resistance requirements.
14. Heat treatment (if necessary)
The parts undergo solution treatment, aging treatment, stress relief or hardening treatment to achieve the required mechanical properties and dimensional stability.
15. Surface treatment and finishing
Processes such as anodizing, passivation, electroplating, coating, or shot peening are used to enhance corrosion resistance, wear resistance, and fatigue life.
16. Final Dimensioning and Appearance Inspection
Complete inspection of finished parts is carried out, including dimensional accuracy, surface quality and appearance defects, to ensure compliance with all specifications.
17. Non-destructive testing (NDT) (if required)
Methods such as penetrant testing, ultrasonic testing, or X-ray testing are used to detect internal or surface defects in critical aerospace components.
18. Documentation and traceability control
Prepare inspection reports, material certificates, process records, and compliance documents to maintain complete traceability and be ready for audits at any time.
19. Cleaning and Maintenance
Clean the parts to remove machining residues and maintain them using approved methods to prevent corrosion or contamination during storage and transportation.
20. Packaging and Delivery
All components are packaged using aerospace-grade methods to prevent damage, maintain cleanliness, and ensure safe delivery to customers.
Industry standards and regulations for CNC machining of aerospace parts
| Standard / Regulation | Explanation |
| AS9100 (Quality Management System) | Aerospace-specific QMS standard based on ISO 9001, with additional requirements for risk management, traceability, configuration control, and quality assurance in aviation, space, and defense manufacturing. |
| ISO 9001 (Quality Management System) | International standard specifying quality management principles, process control, documentation, and continuous improvement applicable across industries. |
| NADCAP (National Aerospace and Defense Contractors Accreditation Program) | Industry-managed accreditation program focused on special processes (e.g., heat treating, coatings, NDT) used in aerospace and defense supply chains. |
| National Aerospace Standards (NAS) | U.S. aerospace industry standards for parts (fasteners, fittings, connecters) and systems maintained by the Aerospace Industries Association; recognized by FAA for parts approval. |
| Aerospace Material Standards (AMS) | Material specifications published by SAE International that define alloy composition, properties, and manufacturing requirements (including machining allowances). |
| ASME Y14.5 (Geometric Dimensioning & Tolerancing) | Standard for GD&T symbols, definitions, and practices used to specify and interpret geometric tolerances on engineering drawings. |
| ASME Y14.41 (Digital Product Definition Data Practices) | Defines practices for preparation and revision of digital CAD models and model-based definition used for manufacturing and inspection. |
| Technical Standard Orders (TSO) | FAA performance standards for specified materials, parts, and processes used on civil aircraft; compliance allows installation under type certificates. |
| AS9102 (First Article Inspection) | Standardized procedure for first article inspection with full dimensional reports and part verification records. (Referenced within AS9100 context) |
| AS9110 / AS9120 (Related AS91XX series) | AS9110 focuses on maintenance/repair quality systems; AS9120 on aerospace parts distribution and traceability. |
| FAA Regulations (e.g., 14 CFR Part 21) | Federal Aviation Administration regulations governing certification of aircraft parts and manufacturing processes. (Associated with TSO/Type Certification) |
| EASA Regulations | European counterpart to FAA regulations governing certification and approval of aerospace parts and processes. |
| ISO/IEC 17025 (Laboratory Competence) | Specifies competence requirements for testing and calibration laboratories. |
Design considerations for aerospace components
Engineers designing complex CNC parts for aerospace applications need to consider several important aspects to ensure that each part meets the stringent quality standards of the aerospace industry and that parts with complex designs and ultra-high precision standards can be manufactured. Other important aspects to consider include:
| Functionality | The parts must be manufactured to the correct specifications, possess the necessary strength and durability, and be able to withstand the harsh operating conditions of the aerospace environment. |
| Manufacturing process | The design must be optimized for the manufacturing process used to produce the part. |
| weight | Aerospace components must be designed to be as lightweight as possible to reduce the overall weight of the aircraft and improve fuel efficiency. |
| Material | Material selection is crucial. Materials must possess the required strength, stiffness, and thermal properties to meet the requirements of specific applications. |
| tolerance | The manufacture of aerospace parts must adhere to strict tolerances to ensure proper assembly and functionality. |
| Load and stress | Aerospace components are subjected to various loads and stresses, such as thermal loads and vibrations. |
| Security and Authentication | Manufacturing in the aerospace industry is governed by stringent regulations designed to ensure the safety and reliability of aircraft and their components. Manufacturers must comply with the regulations of the U.S. Federal Aviation Administration (FAA), the International Trade in Arms Regulations (ITAR), and quality management system standards. |
Design for Manufacturability (DFM) for CNC-manufactured parts in aerospace projects
Design for Manufacturability (DFM) plays a crucial role in ensuring affordable manufacturing costs in the aerospace industry. DFM tightly links design goals with actual manufacturing processes. You must follow DFM principles to reduce production costs by 15% to 40%. The following are some relevant lessons learned by Elimold.
| Optimize tolerances | Pay attention to tolerances that are critical to the function of the part. Setting tolerances smaller than ±0.05 mm will generally increase machining time and cost. For non-critical features, using looser tolerances can simplify machining. |
| Add corner radius | Use a minimum interior corner radius of 0.030 inches (0.76 mm). This is necessary because sharp corners force the use of small-diameter tools, which doubles the programming time. |
| Maintain a consistent wall thickness | Maintain a wall thickness of 0.8 mm (0.03 inches) or more. A thicker wall helps prevent warping and vibration during machining. Conversely, a thinner wall is more susceptible to deformation under cutting forces, leading to errors. |
| Align features with axes | Holes and slots should be placed parallel to the X, Y, or Z axis (along three axes). This is because five-axis machining costs 300% to 600% more than three-axis machining. Good alignment reduces setup changes and avoids complex programming. |
Common materials used in manufacturing custom aerospace CNC parts
Materials required for manufacturing parts for aerospace applications must be strong, durable, lightweight, and corrosion-resistant. Commonly used materials are roughly those listed in the table below.
| Material Category | Material / Grade | Brief Description (Aerospace Context) |
| Aluminum Alloys | Aluminum 2024 | High strength and fatigue resistance; commonly used in stressed airframe structures. |
| Aluminum 2014 | High strength with good machinability; used for heavy structural components. | |
| Aluminum 6061 | Excellent machinability and corrosion resistance; suitable for general-purpose aerospace parts. | |
| Aluminum 6082 | Higher strength alternative to 6061; used in structural applications. | |
| Aluminum 7050 | Improved stress-corrosion resistance compared to 7075; used in thick airframe sections. | |
| Aluminum 7075 | Very high strength-to-weight ratio; widely used in critical structural components. | |
| Titanium Alloys | Ti-6Al-4V (Grade 5) | Outstanding strength, fatigue resistance, and heat performance; widely used in engines and structures. |
| Ti-6Al-4V ELI | Enhanced fracture toughness for critical aerospace applications. | |
| Titanium Grade 2 | Commercially pure titanium with excellent corrosion resistance and formability. | |
| Titanium Grade 9 (Ti-3Al-2.5V) | Good strength with improved cold formability; often used for tubing and fittings. | |
| Nickel-Based Superalloys | Inconel 718 | Exceptional high-temperature strength and creep resistance; difficult to machine. |
| Inconel 625 | Excellent oxidation and corrosion resistance at elevated temperatures. | |
| Rene 41 | High-temperature fatigue and oxidation resistance for engine components. | |
| Waspaloy | Superior strength and stability in extreme engine environments. | |
| Cobalt-Based Alloys | Stellite | Excellent wear, corrosion, and heat resistance; used for high-wear aerospace parts. |
| Stainless Steels | 17-4 PH | Precipitation-hardened stainless steel with high strength and corrosion resistance. |
| 15-5 PH | Improved toughness and dimensional stability over 17-4 PH. | |
| 300 Series (304, 316) | Excellent corrosion resistance with moderate strength. | |
| 410 / 420 | Hardenable martensitic stainless steels for wear-resistant components. | |
| Alloy Steels | 4130 | High strength and good fatigue performance; commonly used in aircraft structures. |
| 4140 | Heat-treatable steel with high toughness and wear resistance. | |
| 4340 | Very high strength alloy steel for highly stressed aerospace components. | |
| Maraging Steel | Ultra-high strength with excellent dimensional stability after heat treatment. | |
| Tool Steels | A2 | Air-hardening steel with good wear resistance for tooling and fixtures. |
| D2 | High-carbon, high-chromium steel with excellent abrasion resistance. | |
| H13 | Hot-work tool steel used in aerospace tooling and molds. | |
| Magnesium Alloys | AZ31B | Extremely lightweight and highly machinable; requires corrosion protection. |
| AZ91D | Higher strength magnesium alloy for aerospace housings and covers. | |
| Copper Alloys | Beryllium Copper | High strength, fatigue resistance, and electrical conductivity. |
| C101 / C110 Copper | Excellent thermal and electrical conductivity. | |
| Bronze (C630, C932) | Good wear resistance for bushings and bearings. | |
| High-Performance Plastics | PEEK | High mechanical strength, chemical resistance, and thermal stability. |
| PEKK | Improved temperature resistance and flame retardancy over PEEK. | |
| Ultem (PEI) | Flame-resistant, lightweight thermoplastic for aircraft interiors. | |
| PPS | Excellent chemical resistance and dimensional stability. | |
| PTFE | Extremely low friction and high chemical resistance. | |
| Engineering Plastics | Nylon (PA6, PA66) | Lightweight, machinable plastic for non-structural components. |
| Delrin (POM) | High stiffness and dimensional stability; low moisture absorption. | |
| UHMW-PE | Excellent wear resistance and low friction. | |
| Composite-Related Materials | G10 / FR4 | Glass-fiber laminate with good strength and electrical insulation. |
| Carbon Fiber Laminates | High stiffness and low weight; machined for precision aerospace components. | |
| Refractory & Special Alloys | Hastelloy | Exceptional corrosion resistance in extreme environments. |
| Monel | High strength and corrosion resistance in fuel and hydraulic systems. | |
| Molybdenum Alloys | High melting point and thermal stability for extreme applications. | |
| Tungsten Alloys | Very high density and heat resistance for specialized aerospace uses. |
Common aerospace CNC-manufactured custom parts
The table below shows the custom aerospace parts that Elimold frequently manufactures and their respective functions, which are crucial for the performance of aircraft and spacecraft. We can meet the relevant precision and standard requirements.
| Part Name | Component Function |
| engine turbine blades | Generate propulsion |
| Avionics housing | Protect and house navigation and communication systems |
| Structural support | Provide structural support and attachment points |
| Control surface actuator | Controlling the attitude and direction of the aircraft |
| Landing gear assembly | Support the aircraft during takeoff and landing |
| Custom fuel tank accessories | Promote fuel storage and distribution |
| hydraulic actuator | Operating various aircraft components hydraulically |
| Custom electrical connectors | Power and signal transmission between components |
| structural slab | Provides strength and rigidity to the fuselage |
| Dashboard | Home-use instruments for monitoring aircraft systems |
Advantages of CNC machining for the aerospace industry
Numerical control (NC) machining is by far the most widely used technology in the aerospace industry because it can produce high-quality, complex parts that meet specific requirements. These precision machine tools play a crucial role in manufacturing complex components needed for aircraft and spacecraft, offering several advantages over traditional machining methods:
Meets the precision requirements of the parts
Precision in aerospace machining is critical to ensuring safety. Safety, optimal performance, material integrity, and compliance ensure reliable part operation and the ability to withstand extreme conditions. Five-axis CNC machine tools can move cutting tools along five different axes, enabling the production of complex parts with precise tolerances. This reduces the need for multiple setups and increases production efficiency.
Obtaining consistent parts
CNC machining can provide consistent and repeatable results, which is crucial for the manufacture of aerospace parts, as these parts must meet stringent performance and safety requirements.
Rapid and efficient mass production of parts
CNC machining is a fast and efficient manufacturing process. Five-axis machining combines multiple operations into a single setup, significantly shortening the production cycle of parts. It also supports automation and unattended operation, improving manufacturing efficiency and enabling rapid iteration in prototyping and aerospace design.
Low-cost manufacturing of high-precision parts
Compared to other manufacturing methods, CNC machining is more cost-effective, especially suitable for small to medium batch production or parts with complex shapes. CNC machining requires less manual operation, thus reducing the risk of human error.
Future Development of CNC Manufacturing Technology for Aerospace Components
As the aerospace industry continues to evolve, CNC machining is also advancing. Advanced technologies such as intelligent automation, enhanced five-axis CNC machining, and hybrid manufacturing (combining CNC machining and 3D printing) promise to improve efficiency and precision. As aerospace component manufacturers adapt to new circumstances, Daguang remains at the forefront of the industry, driving innovation in future aircraft.
Hybrid manufacturing system combining additive manufacturing and CNC technology
The combination of additive manufacturing (AM) and traditional CNC machining has created a hybrid manufacturing system that integrates the advantages of both technologies. This combination enables more flexible design capabilities, faster prototyping speeds, and the production of lightweight, high-strength components necessary for aerospace applications.
Laser Beam Melting (LBM) Process
LBM is an additive manufacturing technology that directly uses metal powder to create complex parts. This process is ideal for producing lightweight structures with complex internal features that are difficult or impossible to achieve using conventional CNC machining alone.
Predictive maintenance and quality control of CNC machine tools
Artificial intelligence (AI) and machine learning (ML) are increasingly being applied to CNC machining to enable predictive maintenance and quality control. These technologies can analyze data from machine sensors to predict when maintenance is needed, thereby preventing unexpected downtime and reducing maintenance costs. Furthermore, AI and machine learning algorithms help detect potential defects during the machining process, ensuring that all parts meet the stringent quality standards of the aerospace industry.
CNC machine tool tool wear monitoring system
Advanced AI-powered tool wear monitoring systems are under development to predict the lifespan of cutting tools and optimize their replacement schedules. By accurately predicting tool wear time, these systems help reduce tool-related costs and ensure consistency in machining operations, thereby reducing the likelihood of part defects and rework.
CNC machine tools, collaborative robots, and robot integration
Collaborative robots (cobots) are being integrated into CNC machine tools and can work in conjunction with human operators. They can perform repetitive or hazardous tasks without the need for numerous guardrails, thus improving efficiency and safety.
Elimold’s CNC machining capabilities for aerospace precision parts
Our capabilities allow us to manufacture custom aerospace parts that meet the most stringent industry standards. Furthermore, Elimold continuously innovates its in-house CNC machining processes. Whatever the tolerances required for your aerospace parts project, our team of engineering experts has the knowledge and experience to handle these challenges. We have an outstanding track record of providing our clients with the highest possible precision.
When other CNC machining companies deem your aerospace machining requirements unattainable, Elimold always looks forward to your call. We are ready to work with you on every detail to ensure the final product meets your unique requirements. Upload your design files now, and our rapid quotation team will generate a quote for you within minutes.
in conclusion
From the production of critical components to research and development activities, CNC machining will continue to provide the aerospace industry with a wide range of precision-customized parts . As the aerospace industry continues to evolve, driven by the relentless pursuit of innovation and excellence in aerospace engineering, the reliance on this advanced manufacturing process will also grow. By continuously optimizing and enhancing the CNC machining capabilities of in-house facilities, stakeholders can ensure that the production of aerospace components meets the highest standards, thereby addressing the challenges facing the aerospace industry today and in the future.
FAQ
What tolerances are typically required for CNC-machined aerospace parts?
Tolerances for aerospace parts are typically between ±0.0001 inches and ±0.01 millimeters. Critical engine and structural components often require even tighter tolerances to ensure safety and reliable performance.
Does CNC machining help aircraft manufacturing achieve faster production times?
CNC machining simplifies complex tasks, accelerates production cycles, and streamlines manufacturing processes. This efficiency ensures the high precision required for aerospace parts while significantly reducing project lead times.
Can CNC machining accommodate complex geometries or designs?
Yes, our CNC machining capabilities excel at handling complex shapes and geometries, making it a versatile solution for complex parts frequently needed in the aerospace industry. This ensures adaptability to diverse design requirements.
What quality control methods are used for CNC-machined aerospace parts?
We prioritize quality in all operations and implement rigorous quality control procedures throughout the CNC machining phase. Our ISO certification process underscores our commitment to providing aircraft parts that not only meet but exceed industry quality and reliability standards.
Why are CNC machining needed in aerospace projects?
Because it ensures the high precision and consistency required for aerospace projects, especially when manufacturing parts used in aircraft and spacecraft. It can produce complex, critical parts with tight tolerances, which are crucial for the safety and reliability of aircraft and spacecraft.
When is a hybrid additive manufacturing and CNC approach best suited for the aerospace industry?
Hybrid additive CNC technology is ideal for producing complex, lightweight components such as engine parts. This approach combines the design freedom of 3D printing with the precision of CNC finishing, thereby reducing waste and shortening delivery cycles.