The Ultimate Guide for Prototype CNC Machining

Machining metal parts is where CNC prototyping is essential. Various manufacturing industries benefit from such state-of-the-art processes.

This ultimate guide will help you understand more about its advantages, limitations, processes, and more.

Keep reading while learning!

Prototype CNC Machining

What is Prototype CNC Machining

CNC prototyping forms a segment or lesser product sets. This process achieves specific designs before its custom manufacturing operation. The CNC prototype obtains certain product samples that are desired to improve at a reasonable cost.

The mentioned prototype machines can help the R&D procedure. They give the design team proof of concept before customization. Moreover, using such machines is also efficient for the company’s product development. Fulfilling the accurate look and functions of finished product parts.

Why Is It Important

Prototype CNC machining is an important method in most industrial project production. By prototype machining, the potential threats or failures are lessened. And that improves manufacturing efficiency. Additionally, doing such a process may decrease the released substandard items chances.

CNC prototyping quickly determines product issues and possibilities. That helps the manufacturer what or how to rectify the possible problems before the production stage. Since the prototype trouble identification is at the primary level, it saves manufacturing time.

Industrial Applications

Medical Industry

Medical items made with CNC machining can be of excellent quality and functionality. It creates new opportunities in the field, including prosthetics and modern tools.

CNC prototypes can make precise medical tools, including safe enclosures, MRI machines, research devices, implants, and more.

Aerospace Industry

The industry continuously uses such processes, inspecting and examining newly developed components functions. Material testing also undergoes such a process. Some components the process produces are bushings, manifolds, gear ports, and more.

Aerospace Industry

Automotive Industry

Automobile companies develop new models and components. That makes CNC machines for prototyping essential for them. They add such equipment for their manufacturing line.

Similar to aerospace, prototyping helps them ensure the parts’ performance and accuracy. The process forms precise gears and tight tolerance components.

Oil and Energy

The oil industry needs components with excellent strength, making them perform well in mining operations and resource extraction. CNC milling prototypes and other processes achieved such features with accuracy.

Military & Defence

Making most ammunition and military vehicles requires complex tools that perform well. This time prototype machining is needed to achieve such tools with specific features. It can make devices, like transportation parts, ammunition, communication parts, and more.

Construction Industry

The construction field choose CNC machining for creating various needed materials. Unlike injection molding methods, the CNC process reduces manufacturing time and cost.

Why Use CNC Machines for Prototyping


Multiple components can be produced using a CNC prototype with the same level of extract precision.

The CNC’s standout characteristic is its ability to produce identical parts consistently. Low tolerances are required for this technique to be successful.

High Accuracy

CNC provides excellent movement control and is highly accurate when employing cutting tools. These are constructed using key elements to fulfill their intended function.

Saves Time

It does not require additional molding or other prerequisites, which can need an extended period.

CNC is a fast-phase process. It can alter CAM/CAD files, enabling changes to prototypes. It quickly returns after undergoing further machining.


Manufacturers that use the machine for CNC prototypes save more money.

That is because a small batch of prototypes can fix any mistakes or flaws. Consequently, they can be avoided in such meters rather than detected in massive amounts.

Material Adaptability

CNC prototyping is suitable for a comprehensive material range. From the most robust metals to other materials like plastics.

As a result, it contributes a considerable benefit. The prototype procedure can bring out using the same material and finished component.

High Tolerance

Finally, using CNC machines for prototyping provides a high tolerance range. Designers can make prototype designs detailed like the desired final products.

What Limitations does the Process Have

What Limitations does the Process Have

Geometrical Limitation

CNC cannot create specific geometries. The internal components for prototyping are one of those.

Some production techniques, like inclusive manufacturing, are preferred for forming geometries. They operate on the inside out.

Environmental Unfriendly

Since prototyping is a reduction process, it completely generates waste. Immense product parts are removed during the procedure. Chipped metals are formed yet useless. That allows manufacturers to dispose of them.

Expert Needs

Experience and expertise in this technological field are needed for CNC prototyping. Operating and creating CAD files are a part of the requisite skill set.

Material Used for CNC Prototypes

Choosing the best materials requires good attention to detail. That’s because it will signify their result. Given the variety of materials accessible, it follows each one has a unique set of qualities. Take a look at the following details.

Aluminum. This material is among the most recommended and used for prototyping. Its physical properties are primarily ideal for mechanical components. They have a thick, corrosion-resistant oxidized layer and are sturdy.

Stainless Steel. Particularly austenitic are preferably used in CNC machining for their capacity. With its crystallinity, this material can tolerate heat attributed to its structure. They are nonmagnetic, seeing stainless steel cannot be hardened.

Brass. Since its mechanical properties are high at many levels, such as strength and tensile, they are excellent in machinability. These qualities are great for locks, valves, bearings, and gears. Components made from brass operate smoothly at high speeds.

Steel. Low price, weldability, and machinability are some of the vital qualities of steel in CNC machining. They are accessible to numerous types of grades, with each unique advantage. The chemical composition of this substance is sought after by most industries.

Magnesium. The said material is increasingly used for machining. It possesses the ideal qualities in terms of weight and machinability. With shorter chip forming, the process can generate exceptional surface finishes.

Copper. Its attributes are used the most in various applications. Basis characteristics of CNC machining include electrical conductivity, excellent resistance, and heat. These are found in copper, which makes them perfect for parts fabrication.

Titanium. For the medical industry, this material is perfect to a high standard. This metal is non-toxic, biocompatible, and resistant to corrosion. Additionally, due to the extraordinary features of this material, they are simple to machine.

CNC Prototype & 3D Printing Differences

Supported Materials

Various material resources for CNC machining are available. It can support metals, plastics, and even wood.

However, 3D printing is limited. Since this method involves warming and molding, it only operates with thermoplastic prototypes excellently.

Mode of Action

With reduction manufacturing, CNC uses a cutting tool to get rid of any extra element before forming into the desired shape.

3D printing uses the additive method. The material is added gradually by melting and molding it from scratch.


The subtractive manufacturing process of CNC tends to create more waste. But these can be covered since they can sell as recycles.

On the contrary, 3D prototyping effectively utilizes materials. It employs additive manufacturing methods, which are clean-cut.

Production Period

CNC machining is significantly way faster than 3D printing. It only takes them to complete the components within a couple of minutes.

But 3D printing takes more time, like hours to finish a single section.

Potential Geometry

In internal geometries, creating parts with 3D-printed are complex. Due to the reason that from inside out, components are made.

An external cutting tool is used to create the CNC components. It cannot, therefore, produce practical prototypes in complex interior geometry.

Computer-Aided Design for CNC Machining

Making Design Checklist

Before beginning to design, making checklists is essential. You can take down features and structures of desired prototyped components. Having such lists may reduce mistakes during the process.

Design Development

Developing design parts, including holes and cavities is essential in CNC machining. It is important to define and control parts specifications. For example, in final milling, the increased depth has about 3x of the cavity diameters.

Wall Thickness

It is important to ensure the minimum wall thickness when making a sample drawing. Metal walls are required to have over 0.8mm thick. Too thin walls may cause decreased machined component mechanical consistency.

CAD Software Best Option

CAD Software Best Option

Different manufacturing industries have specifically suitable CAD software. Selecting the best ones is essential. As some others are limited for certain usages. Ensure the ideal CAD according to metal forming, mechanical engineering, and prototyping needs.

Simple Drawing

Always ensure easy-to-understand drawing. Make sure of easy-to-define design features and other factors, including pictures, symbols, and shapes. Making your design simple can contribute to prototyping efficiency and accurate outcome.

Design Quality Inspection

After the final design, it is also recommended to review the design specifications listed on the checklists. That will help you determine if there’s any deletion or inclusion. Inspecting designs allows you to adjust them before the operation started.

How to Save CNC Prototyping Cost

The following defines the important tips for managing prototype production process costs.

  1. Utilizing the exact material

Suitable material selection is the number one important factor to consider. Before deciding, it is advised to consider the following material application requirement.

  • Strength
  • Weight
  • Finishes
  1. Use various machine

Having multiple disposal machines allow you to save money. They can be operated simultaneously. Installing such equipment will reduce installing time needed for every machine.

  1. Machined Component

Using CNC-machined components or prototypes can save money. Since they are formed with high durability and stronger features compared to traditional-made ones.

  1. Order in Bulk

Ordering bulky CNC prototypes can save overall costs. Some companies and manufacturers, like HM offer discounts for bulky orders.

  1. Choose a Trusted Manufacturer

Choosing the most trusted and veteran manufacturers can minimize the overall project money. You can browse different companies before deciding. HM always make sure of immediate online quote for your requested prototypes.

Selecting Ideal Machining Technique

To customize your prototype, there are various processes involved. And the following details will help you define the suitable ones for your project needs.

Calculated Usage

The component application that needs to be processed is one factor to include in prototyping method selections. If they are for high-tolerance usage, then laser cutting is needed. For presentation, the affordable prototyping technique is recommended.


The material category also defines suitable machining methods. For instance,

  • Sheet metal cutting needs a CNC laser cutter
  • Forming 3D components requires CNC milling equipment

Knowing every material’s strengths, features, and hindrances can help in selecting the right process.

Components Geometry

The final components’ structure affects the accurate prototyping technique used. The parts with,

  • Round cross-section – needs drilling process for holes
  • 3D surface style – needs CNC lasers and CNC mills

CNC Prototyping Processes

CNC Milling

The CNC milling process utilizes milling equipment that rotates the tools. That functions as a profile or pocket cutter, requiring deep cuts. It forms

  • Tapped holes
  • Slots
  • Blind holes
  • Precise holes
  • and undercuts

The milling machines come with 3 and 5-axis mills capacity. They are effectively used in rapid manufacturing and structural designs.

CNC Turning

CNC Turning

The CNC turning method uses automated lathe machines, making the workpiece rotate. It is an effective process of forming a cylindrical or circle part structure.

The CNC turning machine is programmed to;

  • Cut or remove the exterior elements
  • Bore or drill
  • Cut the internal and external threads

Involved Metal Fabrication Steps

Welding. This process can join the different metal parts into a new piece. It utilizes various tools and methods.

Extrusion. The operation occurs as metal goes through a closed or open die. Metals are compressed in this process.

Stamping. Certain letters, images, and shapes are imprinted on the metal during this fabrication.

Bending. Pressing the metals with a heavy machine. It shapes them into the specific form required.

Spinning. Forming the metals happens here by utilizing a high-speed tube or disc. That creates an axis-symmetric structure.

Finishing. That includes coatings such as paint, glazes, and other protective covers. It is usually part of the last step.

Cutting. It involves cutting the metals into the desired sections. They are made possible with various cutting machines.

How Much is the Cost of CNC Prototyping?

CNC prototypes’ price is modified according to specific prototype requirements.

Overall, the price range is about $35 to $120 each hour with 3-axis. The complexity of components defines the suitable axis.


Indeed, CNC prototyping helps achieve speedy project production and a practical solution for an economical manufacturing operation.

After reading such a knowledgeable guide about CNC prototyping, you can make decisions according to what you have learned.

For further information, feel free to communicate with us now!

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