Resources
/
Technical Toolbox
/
Engineers Guide to CNC Machining

Engineers Guide to CNC Machining

Mechanical, manufacturing and design engineers often rely on CNC Machining to develop and manufacture bespoke parts. This guide is for engineers designing parts for CNC.

Luke Smoothy.
Luke Smoothy
Published
March 3, 2022
/
Updated
May 19, 2025
A drawing and a pen.

What is CNC Machining in Engineering?

In the realm of engineering, CNC Machining stands as a cornerstone of modern manufacturing. It leverages the power of Computer Numerical Control (CNC) to transform digital designs into tangible components with unparalleled precision. Engineers harness this technology to create bespoke parts, ensuring consistent quality and repeatability. Whether it's for prototyping or mass production, CNC Machining offers engineers the flexibility and accuracy needed to meet the rigorous demands of today's engineering projects.

Generally, the term CNC Machining is a manufacturing process that uses subtractive machining technology and Computer-Aided Design (CAD) to manufacture high-quality components. Having a computer control this process means there is a reduction in lead times and also reduced human error, leading to a high-quality and highly precise output.

CNC Machining can be used for bespoke, one-off parts through to mass production runs.

To fully benefit from the mass production and high-quality parts that CNC Machining offers, engineers should know how CNC Machining works and fundamental factors that affect the process.

{{cta-banner}}

The cost of CNC Machining

The cost of CNC Machining varies from project to project and depends on the material, complexity and quantity of the parts to be machined. Other factors such as how the end product will be used and additional finishes and tolerances will influence the cost also. Most materials can be CNC machined, including most metals and plastics. Wood, foam and composites can also be CNC machined, however, Get It Made specialises solely in metals and plastics. Less dense materials are typically quicker to machine as the CNC Machine can operate at a higher feed rate. Reducing machining time is one of the key drivers for reducing the cost of CNC machining.

Request a free CNC Machining quote from Get It Made today.

Considerations for Engineers

When designing a part for CNC machining, further considerations that engineers should be aware of include the overall part size and the number of reorientations required to machine the part. These directly influence the machining and setup time. This affects not only the cost of the part but also the lead time. If you require CNC parts fast, look to reduce the complexity of the design and ensure the machining can be completed in as few operations as possible.

Read our detailed CNC Machining Guide here.

Tolerances

Engineers need to use realistic tolerances on initial drawings and designs that reflect how the final part will be used and how it interfaces with other components. Overly tight tolerances increase costs and lead times, therefore try to determine the tolerance you require instead of specifying a generic tolerance.

A pair of scissors sitting on top of a piece of paper

What are the tolerances in CNC Machining?

Tolerance refers to the range for a dimension, and a designer or engineer will determine the tolerance based on the form, function, and fit of the part. Most parts will have a maximum and minimum dimensional limit. Standard CNC tolerances are determined by the type of CNC process being applied. For example, the CNC tolerance in CNC turning can be controlled more tightly than that of CNC machining.

There are many different types of tolerances, such as positional, flatness, parallelism, thread tolerances etc. We recommend familiarising yourself with GD&T (Geometric Dimensioning and Tolerancing), which is a methodology and language for communicating engineering tolerances.

You can find more information on the types of metal used in CNC machining by reading this guide, Choosing the Right Metal for CNC Machining.

CAD File Formats

CAD file formats are another factor for design engineers to consider when designing a part for CNC. Various software packages and file formats may not be compatible with CNC machining, and it is vital to consider the type of CAD software you are using, too.

You can read our detailed guide on CAD File Formats for CNC Machining here.

Best CAD Software for Engineers

To create CAD files to input into a CNC machine, a CAD software package is needed. The CAD software you choose will depend on the cost, ease of use, and file compatibility of the software. The five industry-leading CAD software packages are:

  • SolidWorks
  • Autodesk Inventor
  • Creo
  • Siemens NX
  • Catia

You can read more about CAD software in our detailed guide to CAD software for CNC Machining.

Types of CNC Machine

CNC Machining is sometimes used as an all-encompassing term to describe the various types of computer-controlled subtractive machining technologies such as:

You can find our detailed Guide on Types of CNC Machine here.

To find out more about our range of CNC Machining services, arrange a free quote today or discover our range of CNC Machining services here. Head to our technical toolbox for our full range of machining knowledge.

A large metal object on a white background
A pair of metal latches on a black background

Leave it to our manufacturing specialists

Get a 24 hour, engineer made quote and design review to start your manufacturing project off on the right foot

A man wearing glasses and a white shirt

Get your production-ready quote in 24 hours

All projects are reviewed by real engineers to ensure accuracy, catch mistakes and unlock DFM improvements

Luke Smoothy.
Luke Smoothy
/
Director and Founder

Obsessed with making sure we offer the best service possible in the manufacturing industry. Father to one, and hopefully many more!

Working with Get It Made for all our prototyping was an absolute pleasure. Next to immediate response, fast lead times, often arriving before the stated date. Their attention to detail and customer service were second to none. and all at the most competitive price point that could't be beaten in the U.K.
Ben Coughlan
Ben Coughlan
Director - Sneek Films Ltd
Precision machined metal cube with multiple threaded circular holes
Get It Made are at top of their game when it comes to reliability and quality. We trust Get It Made to deliver parts on time and within tolerance. We can't speak highly enough of their customer service. Get It made are quick to reply to enquiries and keep you well informed throughout the whole process.
Max Blake
Max Blake
Designer - Max Blake Design
Metallic cube with multiple precision-machined cylindrical holes
Get It Made were able to deliver an accurate and quick service delivering a set of high fidelity prototypes expertly finished, ready for user testing. They offered a range of fabrication options and materials to choose from, tailoring the service to our specific budget, timeframe and material requirements. Can't recommend enough.
Finlay Page
Finlay Page
Head of Product - Robotical Ltd
Precision machined metal cube with multiple threaded circular holes
Get It Made have over the years been able to take on from simplest to the most complicated of jobs with ease, providing expert advice, good prices and reliable lead times. No job has been too big or too small, either in size or volume. We would strongly recommend Get It Made; you won't be disappointed!
Stuart Leslie
Stuart Leslie
Director - Bann Engineering
Metallic cube with precise machined holes and threaded openings
We initially started working with Get It Made, as we needed a high quality product developed within a very short lead time. The entire process went very smoothly and we received the products ahead of schedule. We were pleased with the final results and we found working with Luke very easy, as he offered good technical advice.
Tom Butterfield
Tom Butterfield
Designer - Tom Dixon
Precision machined metal cube with multiple threaded circular holes
When we were looking to have parts manufactured, we had tight deadlines with an even tighter budget. Get It Made understood our constraints and worked with us closely to get our parts to a higher standard than we expected. I can not recommend Get It Made enough. They are professional, communicative, and the parts are fantastic.
Ross Embleton
Ross Embleton
Head Of Research And Development - Heliguy
Precision machined metal cube with multiple threaded cylindrical holes
The Get It Made team are very responsive and knowledgeable, fully owning a project throughout, providing superb communication. Transparent pricing structure and rapid quotation turnaround is by far the quickest I've experienced, reducing time to manufacture. Get It Made are a pleasure to work with.
Ollie Masters
Ollie Masters
Lead Process Engineer - Karakuri
Metallic cube with multiple precision-machined cylindrical holes
All testimonials

Bespoke quote in 24 hours

Get It Made is proud to provide a human service. Get a quote and free design review by an experienced engineer to see how we make manufacturing simple.

Cookie Settings
By clicking “Accept”, you agree to the storing of cookies on your device to enhance site navigation, analyse site usage, and assist in our marketing efforts. View our Privacy Policy for more information.