Machining Services


Provide efficient production and faster design to delivery.


Produce precision parts that exceed industry standards.


Create and test products quickly to bring them to market.

Consumer Products

Bring new, affordable products to market faster.


Empower to innovate faster, maximizing performance.


Innovation in enclosures for low-volume production.

Industrial Equipment

Deliver machinery that beats the competition.

New Energy

Speed up innovation and development.

Medical Devices

Build prototypes and products that adhere to medical safety.


Improve efficiency with precise, fast, and constant part quality.


Drive time-to-market through on-demand production.

CNC Machining for Aerospace

The extremely high level of precision needed within the aerospace industry makes CNC machining a suitable manufacturing process for the sector.


This article provides you with a complete guide to aerospace machining and its importance.



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Case Studies

Learn successful stories to inspire your project.

Surface Finishes

Select from 30+ surface finishing options.


Choose from 50+ metals and plastics for your project.

CNC Machining eBook

If you want to produce high-quality machined parts with a sleek appearance, it’s essential to consider some critical factors related to CNC machining. 


Here, we’ve gathered some basic information and important considerations to help you achieve the desired results.

About RapidDirect

Our vision, mission, development history, and dedicated team.

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Get instant quotes with our smart online platform.

Quality Assurance

Deliver quality parts that meet requirements and exceed expectations.

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Instant Quote for Sheet Metal Fabrication and New Homepage

Exciting news from RapidDirect!  We’ve rolled out two exciting updates to enhance your manufacturing journey. 

  • Instant Quote for Sheet Metal Fabrication
  • A brand-new Homepage Experience

Custom Online CNC Machining Services

Get instant online quote for your metal or plastic CNC machined parts, from rapid prototyping to production. Choose from 100+ materials, 60+ surface finishes. ISO 9001:2015, ISO 13485, ISO14001:2015, IATF 16949:2016 certified. Experience lead times as short as 1 day.
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CNC Machining Services for Custom Parts

Our advanced milling centers and turning equipment deliver precision with tolerances as tight as 0.001 inches. Beyond standard machining, we provide value-added services like CNC routing, EDM machining, and precision grinding, perfect for designers and product developers seeking to actualize innovative ideas with top-quality custom components. Whether the project is straightforward or complex, our equipped machine shops are ready to take it on. We guarantee not only superior quality but also rapid delivery—custom simple machined parts are shipped within just 1 day. Get started.
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Custom CNC Milling Services

CNC milling employs multi-axis operations, such as 3, 4, and 5-axis machining, to ensure precision and intricate geometries from blocks of metal or plastic, efficiently producing complex parts.

  • Tolerances as tight as +/- 0.001 inches.
  • Custom milled parts for prototyping and production.
  • Quick turn milling services.
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Custom CNC Turning Services

CNC turning uses CNC lathes and turning centers to shape metal rob stock, focusing primarily on cylindrical turned parts. Ensure components achieve consistent dimensions and smooth finishes.

  • Achieves +/- 0.0005 inches precision.
  • Custom turned parts for prototyping and production
  • Quick turn turning services.

CNC Machining Materials

We work with a wide array of CNC materials, including both metals and plastics. Choose from aluminum, steel, brass, and more for your custom CNC machined parts.

CNC Machining Surface Finishes

Achieve the perfect finish with our range of surface treatments. Whether you require anodizing, plating, or painting, we ensure your parts meet both aesthetic and functional specifications.

As Machined  

As machined (Ra1.6)
As machined finish leaves the surface straight from the CNC machine, providing a cost-effective option with tool marks.


Anodizing Type II (Black, Glossy)
Anodizing increases corrosion resistance and wear properties, while allowing for color dyeing, ideal for aluminum parts.


Ra0.2 (Mirror polish)
Polishing achieves a high gloss finish, reducing surface roughness and enhancing the aesthetic appeal of metals.

Sand Blasting

Sand blasting (#220)
Sand blasting uses pressurized sand or other media to clean and texture the surface, creating a uniform, matte finish.


Tumbling smooths and polishes small parts by friction and abrasion in a barrel, offering a consistent but slightly textured finish.


Electropolish is a chemical process that smooths and brightens surfaces while improving corrosion resistance.


Alodine (Chemical film:Conversion) Yellow
Alodine coating provides corrosion protection and improves paint adhesion, mainly used on aluminum surfaces.
Heat Treatment
Vacuum Heat Treatment
Heat treatment alters the mechanical properties of metal to increase its hardness, strength, or ductility.

Brushed Finish

Brushed (#220)
A brushed finish creates a unidirectional satin texture, reducing the visibility of marks and scratches on the surface.

Powder Coating

Powder Coating (Black)
Powder coating applies a thick, wear-resistant layer with excellent color and texture options, suitable for a variety of surfaces.


Nickel Electroplating (Glossy)
Electroplating bonds a thin metal layer onto parts, improving wear resistance, corrosion resistance, and surface conductivity.

Black Oxidize

Black Oxidize
Black oxidize is a conversion coating for ferrous metals that improves corrosion resistance and minimizes light reflection.

Tolerances for
CNC Machining

Our CNC machines operate with precision tolerances that meet industry standards, ensuring that every part is consistently accurate and fits perfectly with other components.

General TolerancesMetals : ISO 2768-m
Plastics : ISO 2768-c
Precision TolerancesRapidDirect can manufacture and inspect parts with strict tolerances according to your drawing specifications and GD&T annotations, including tolerances tighter than +/- 0.001 inches.
Min Wall Thickness0.5mm
Min End Mill Size 0.5mm
Min Drill Size 1mm
Maximum Part SizeCNC Milling: 4000×1500×600 mm
CNC Turning: 200×500 mm
Minimum Part Size CNC Milling: 5×5 ×5 mm
CNC Turning: 2×2 mm
Production VolumePrototoyping: 1-100 pcs
Low volume: 101-10,000 pcs
High volume: Above 10,001 pcs
Lead Time5 bussiness days for most projects.
Delivery of simple parts can be as fast as 1 day.

Design Guidelines for
CNC Machining

Optimize your designs for manufacturability with our helpful guidelines. Our experts provide feedback on your custom machined part for the best results in CNC machining.

RadiiIn CNC machining, sharp internal corners on a workpiece will naturally form rounded corners (radii). The depth must not exceed 12 times the diameter of the drill. For end mills, the depth must not exceed 10 times the diameter of the tool.
Threads and Tapped HolesDiameter Φ 1.5-5 mm, depth: 3 times the diameter.
Diameter Φ 5 mm or larger, depth: 4-6 times the diameter.
RapidDirect can produce threads of any specification and size as required by the customer.
UndercutsSquare profiles, full radius, dovetail profiles.
TextCNC Milling: Minimum width of 0.5 mm and depth of 0.1 mm.
CNC Turning: RapidDirect can use laser marking to create standard text for CNC turned parts.
RapidDirect can create standard text via CNC engraving or laser engraving as per customer requirements.

CNC Machining Solutions

Rapid Prototyping

Accelerate product development with our rapid machining services. We offer fast turnaround times and specialize in quick production of high-quality prototypes and mold tooling, aiding your design verification process.

Low and High-Volume Production

Whether you need small batches or large-scale production, we can offer you both. With stringent tolerance controls and comprehensive capabilities, we adapt to your volume requirements without compromising on quality.

A Robust Network of
CNC Machine Shops

CNC machining begins with a computer design of a part. Machines then precisely remove material to turn the design into a real machined part. This cutting can be done from different angles using machines that have 3, 4, or 5 moving parts, known as axes.


At RapidDirect, we have our own main CNC machine shop and a broad network of partner shops throughout China. Our facilities aren’t limited to just basic CNC machines. We also have grinders for smoothing surfaces, wire cutters for precise cuts, and EDM machines for detailed shapes. This variety allows us to tackle complex designs that produce unique CNC machined parts with specific requirements. Our skilled machinists work with exceptional accuracy, achieving tolerances as precise as 0.01mm. This level of detail is crucial for components that must fit perfectly into larger assemblies.


We also use automated production lines. These are setups where machines work together smoothly and quickly, which helps us produce large quantities faster and reduces the chance of errors. This efficiency means we can deliver quality machined parts quickly to meet our clients’ needs, keeping projects on schedule.


Sets of Machine


Countries Shipped


Customers Served

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Start Your
CNC Machining Project

Kickstart your project with our easy-to-use online quoting platform. Upload a CAD file to receive instantly quotes, lead time, and DFM details for your CNC components. Specializing in CNC machining for metals and plastics, we provide adaptive production and shipping solutions to align with your product development needs.

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CNC Machining for Various Industries

RapidDirect’s CNC machining services cater to a wide range of industries, from automotive to aerospace, ensuring that every sector’s unique requirements are met with precision.

Success Stories of
CNC Machining Projects

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High Quality

Experience unparalleled precision in each undertaking. Our advanced milling processes ensure components adhere to tight tolerances, as tight as ±0.01mm, resulting in seamless assembly and operational excellence.

Fast Lead

Accelerate your manufacturing cycle. RapidDirect domestic workshops and state-of-the-art machinery guarantee fast turnaround times, helping businesses maintain momentum and meet critical deadlines.


No matter you whenever and whereever, navigate your CNC milling projects with confidence. Our seasoned specialists offer insightful guidance at every step, maximizing design optimization and output quality.

Ultimate Guide to CNC Machining


CNC machining has a wide range of applications across industries.

  • In the automotive and aerospace sectors, it is used to fabricate precise engine components, structural parts, and other intricate elements.
  • The medical industry leverages CNC for manufacturing devices, implants, and surgical instruments.
  • CNC is also crucial in electronics, enabling the production of electronic housings, circuit boards, and connectors.
  • Machine tool makers rely on CNC to create complex molds, dies, and machine components. Additionally,
  • CNC is valuable for general custom part production, prototyping, woodworking, and more, allowing for consistent quality and high precision.

Advantages of CNC Machining

  • Precision and Repeatability: CNC machining ensures high precision and consistent replication of parts, crucial for complex designs with tight tolerances.


  • Reduced Human Error: The automated nature of CNC machining minimizes human error, enhancing the overall quality of production.


  • Efficiency and Speed: Automation allows for faster production cycles, enabling quicker turnaround times than manual processes.


  • Material Flexibility: CNC machines can work with a diverse range of materials, including metals, plastics, and composites, offering versatility across various applications.


  • Software Integration: Advanced CNC software supports quick design changes and updates, facilitating rapid prototyping and easy customization.


  • Cost-Effective for Large Runs: While setup costs are higher, per-unit costs decrease significantly with larger production volumes, making it cost-effective for mass production.



Disadvantages of CNC Machining

  • High Initial Costs: CNC machinery and its maintenance represent significant investments, making initial setup expensive, especially for small-scale operations.


  • Skill Requirements: Operating CNC machines requires highly skilled personnel, which can increase training costs and limit accessibility.


  • Less Cost-Effective for Small Runs: Due to setup and programming time, CNC machining may not be economical for producing small quantities of parts.


  • Material Waste: CNC machining often involves subtractive processes, leading to more material waste compared to additive manufacturing.


  • Limited to Material Hardness: Extremely hard materials can wear out CNC tools quickly, potentially increasing operational costs and downtime.

Manufacturing Process: 3D printing is an additive process, building parts layer by layer from materials like plastic or metal. In contrast, CNC machining is subtractive, cutting away material from a solid block to shape the final product.


Material Efficiency: 3D printing minimizes waste by using only the material needed to form the part, whereas CNC machining can produce more waste due to its subtractive nature.


Speed and Cost: For small batches and complex geometries, 3D printing can be faster and more cost-effective. CNC machining is preferable for larger volumes and materials requiring high precision and strength.


Surface Finish and Tolerances: CNC machining typically achieves better surface finishes and tighter tolerances compared to 3D printing.

John T. Parsons is often credited as the father of CNC machining. In the late 1940s, Parsons developed the first numerical control techniques and applied them to the production of helicopter rotor blades. Working alongside engineer Frank L. Stulen, Parsons conceptualized the method of using punched tape to guide machine tools. This innovation laid the groundwork for the development of CNC (Computer Numerical Control) technology. Their pioneering work eventually led to the creation of the first CNC machines in the 1950s, which revolutionized manufacturing by improving the precision, efficiency, and repeatability of machining processes.

G and M codes are the programming languages used in CNC machining to control CNC machine tools. G-codes are primarily used for specifying the movements of the machine, such as linear interpolation, circular movements, and other specific functions related to the actual path of the tool. M-codes, on the other hand, handle machine functions that are not directly related to the path of the tool, such as turning the machine on or off, starting or stopping the spindle, and controlling coolant. Together, G and M codes provide a comprehensive set of instructions that CNC machines follow to produce parts accurately and efficiently.

CNC machining is renowned for its ability to achieve high precision and tight tolerances, essential for complex and detailed parts. Typically, standard CNC machining can maintain tolerances within ±0.01 inches (±0.127 mm). RapidDirect defaults to standardized tolerances without special requirements. For even more precise requirements, advanced CNC machines can achieve tolerances as tight as ±0.0005 inches (±0.0127 mm) under optimal conditions. The achievable tolerance depends on several factors including the material, part geometry, size, and the specific type of CNC machine used. This capability makes CNC machining a preferred choice for industries that require highly accurate components, such as aerospace, medical, and automotive sectors.

A machining center is a highly advanced CNC machine designed to handle a variety of machining tasks including milling, drilling, and tapping, all within a single setup. This integration enhances efficiency and accuracy by reducing the need to transfer parts between different machines. Machining centers are equipped with a tool turret or magazine that holds multiple tool options, enabling automatic tool changing under CNC control. This capability allows for rapid switching between operations, optimizing production flow. Typically, machining centers are used for complex parts that require precision machining from multiple angles, making them indispensable in modern manufacturing environments.

Certainly! At RapidDirect, we have the capacity to manufacture over 10,000 diverse prototypes each month, ranging from straightforward to complex designs. Our production capabilities are supported by more than 200 state-of-the-art CNC machines. We also take pride in our team of over 100 skilled technical experts who ensure precision and quality in every project. This extensive infrastructure allows us to meet large-scale demands efficiently, making us a reliable partner for all your CNC machining needs. Whether your project is big or small, our resources are geared to deliver with excellence.

The expense associated with our CNC machining service is variable and directly influenced by the distinct attributes of your project, including its design and tolerance specifications. The machining duration for the chosen material is another key determinant of the cost. To illustrate, should you require a part where the combined machining and material expense is $2, with an additional setup charge of $200, the total cost for a singular part would amount to $202. Contrastingly, should you commission the production of 200 identical parts, the cost per unit would be just $3! Learn more about the CNC machining costs.

At RapidDirect, we understand the diverse needs of our customers, ranging from single prototypes to large-scale production runs. Consequently, we do not enforce a strict minimum order quantity (MOQ). Whether you require just one machined part or thousands, we are equipped and ready to provide tailored solutions that meet your specific requirements. Our flexible approach ensures that all clients, regardless of order size, receive the highest level of service and quality.

The lead time for receiving a CNC machined part from RapidDirect can vary depending on several factors including the complexity of the part’s design, the type of material selected, and our current production schedule. CNC machining is known for its speed, particularly for less complex parts, allowing for quick turnaround times. In fact, parts can be delivered in as fast as just one day after the machining setup is complete! However, for the most accurate time estimate tailored to your specific project, we recommend contacting us directly for a detailed quote. This way, we can provide you with a precise timeframe based on your unique requirements.

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