Prototype machining refers to CNC machining for creating rapid prototypes. In most cases, it is the first choice for one-off prototypes in new product development. In this article, we will explore the details of prototype machining, what services are available, when to use it, its applications, benefits, and costs.

What Is Prototype Machining?

When talking about prototype machining, we are talking about CNC machining in rapid prototyping. CNC machining means Computer Numerical Control machining, using the computer to control the machine and tools inside to turn digital CAD objects into physical components.

Prototype machining plays a crucial role in product development by providing a tangible representation of a design. It helps to identify and address potential issues early in the development process.

What Are the Prototype Machining Services?

There are different types of CNC machining techniques for prototype machining. Two of them are the most frequently used processes: CNC milling and turning.

CNC Milling

CNC milling follows programmed instructions to cut, drill, and shape the workpiece to the desired specifications. The workpiece is fastened on a stationary table. The cutting tools can move along multiple axes to create complex shapes, slots, and holes in the workpiece. 

This process is suitable for producing parts with intricate features and details. It is preferred over CNC turning for rapid prototyping and iterative design processes.


CNC Turning

CNC turning involves holding a cylindrical workpiece in a chuck and rotating it while a cutting tool removes material from the outside of the workpiece. The cutting tool can move in two axes to create cylindrical parts, such as shafts, pins, and parts with cylindrical or rotational symmetry. 


Besides CNC milling and turning, there are also other processes for prototype machining, including CNC routing, grinding, cutting, drilling, Electrical Discharge Machining (EDM), etc. They may be applied based on the specifications of the prototype part. Each time you get a quotation sheet with the CNC machining from your supplier, it contains the cost of all processes involved.

When to Use Prototype Machining?

There are nearly no limitations to the geometry of CNC prototype machining. CNC machining can handle from the appearance, structural, and functional prototypes, jigs, and fixtures to production parts in small runs. 

Below is a quick checklist to decide if your part fits prototype machining services.


1 pc or low volume less than 1,000 pcs


Plastics (when the quantity is more than 10 or so, vacuum casting is more economical)

Metals (when the wall thickness is less than 6mm, sheet metal fabrication is more cost-effective)


No less than +、- 0.1mm


CNC machining is ideal for smooth surfaces for further finishing. That's why it is preferable to 3D printing.

Tight turnaround time:

The lead time of CNC machining can be as fast as 3 days.

Benefits of Prototype Machining

Prototype machining excels among other prototyping methods because of the advantages it offers.

Fast Turnaround Time

Prototype machining allows for the quick creation of physical prototypes within days, enabling designers and engineers to iterate and refine designs rapidly.

Design Validation

A physical prototype allows businesses to test the forms, fits, functions, and appearances of the new designs.

Risk Reduction

Identifying and addressing design flaws early in the development process through rapid prototypes helps prevent costly revisions of expensive steel molds during full-scale production.


Prototype machining enables the creation of custom, one-off parts with specific geometries and material properties tailored to the project's requirements.

Wide Selection of Materials

Prototype machining supports various materials, including metals, plastics, composites, and more, allowing for material testing and selection.

Precision and Quality

Machining processes such as CNC milling and turning offer high precision, tight tolerances, and excellent surface finishes, ensuring the production of high-quality prototypes.

Time-to-Market Reduction

By accelerating the design validation process, prototype machining contributes to faster product development and reduced time-to-market for new products.

What Industries Use Prototype Machining the Most?

Many industries benefit from prototype machining in product development and even low-volume production. Below are some typical ones.


Prototype machining is extensively used in the automotive industry to develop and test components such as engine parts, chassis components, and interior features before full-scale production.


Medical Devices

Prototype machining is crucial for developing and testing medical devices, surgical instruments, and custom components used in healthcare equipment. 

It is also used for the production of medical device products. Because the volume is usually low and the traditional mass production processes are too costly for low quantities.



The aerospace industry utilizes prototype machining to create and test complex components, including structural parts, engine components, and specialized aircraft systems.

Consumer Electronics

Industries producing consumer electronics, such as smartphones, tablets, and wearable devices, utilize prototype machining to develop and refine product designs and internal components.


However, CNC machining cannot build PCB components for consumer electronics. Specific PCB prototyping methods are needed. Prototype machining vendors usually can't produce PCB prototypes.

Industrial Manufacturing

Various sectors within industrial manufacturing, including machinery, equipment, and tools, use prototype machining to create and test custom parts and components.

Generally speaking, companies involved in new product development across diverse industries rely on prototype machining to iterate and refine designs before mass production.

How Much Does Prototype Machining Cost?

The cost of prototype machining can vary significantly based on several factors, including the part complexity, the part dimension, the materials, the quantity, the finishing, the tolerances, and the lead time. The unit cost usually starts from $50.

It's vital to consult with your vendors to obtain accurate cost estimates based on the specific requirements of your project. You don't have to trust big companies blindly. 

Additionally, economies of scale can apply, meaning that larger quantities of prototypes may reduce the cost per unit.

Prototype Machining Services Offered by X Rapid Technologies

As a senior player with over 15 years of experience in CNC machining, X Rapid Technologies offers one-stop full-range prototype machining services for prototypes and small series. Get in touch whenever you need a machining solution for your newly-developed parts.

Frequently Asked Questions

1. What materials and finishes are available for prototype machining?

The common plastic materials for prototype machining are ABS, PC, PMMA, PA, and POM. ABS is the cheapest one.

The typical metal materials for prototype machining are aluminum 6061-T6, stainless steel, steel, brass, and copper.

Different materials are suitable for different surface treatments. For plastic CNC-machined prototypes, the finishings are usually deburring, sanding, polishing, painting, electroplating, silk screening, laser engraving, etc. 

For metal prototypes, you can do deburring, sandblasting, polishing, powder coating, electroplating, silk screening, laser engraving, heat treatment, etc.

2. What CNC machines are usually used for creating prototypes?

CNC machines are usually categorized based on the number of directions they can move. Common types include 3-axis, 4-axis, and 5-axis CNC machines. 3-axis CNC machines can nearly meet all prototype machining demands. Complex parts may need 4-axis CNC machines. And 5-axis CNC machines are seldom used because it is not necessary and expensive.

3. What is the average turnaround time of prototype machining?

Generally, the turnaround time for prototype machining can range from a few days to two or three weeks.

Simple prototypes with less complex geometries and standard materials may have a shorter turnaround time of 3 days. 

However, more intricate or specialized prototypes may require additional time for machining and post-processing.

4. Will 3D printing replace prototype machining?

While 3D printing has revolutionized the prototyping and manufacturing industries and even become popular among people, it is unlikely to completely replace CNC machining. Instead, 3D printing complements prototype machining by offering unique capabilities and advantages.

3D printing excels at producing intricate designs that may be challenging or impractical to manufacture using traditional machining methods.

On the other hand, prototype machining, including CNC milling and turning, offers superior precision, surface finish, and material options for certain applications. It is often the preferred method for producing high-precision, functional prototypes, especially when specific material properties or tight tolerances are required.