What All CNC Machining Buyers and Purchase Directors Need To Know (A Guide)

Your company’s new product is going to require CNC machining. It’s on you to find the machine shop that best fits your needs. You may know nothing about CNC machining, and it may seem impossibly complicated, but it’s not. You already know the basic business principles to watch for, and that’s half the battle. This guide can help you with the other half.

Start With the Easy Stuff

Just like any resource search, begin with the basics. These are the same simple factors you always take into consideration when looking for a vendor or supplier. All of this information should be readily available on a company’s website.


How long has the company been providing CNC machining? This single fact won’t automatically decide a company’s fate, but it’s an important factor. Experience pays dividends as long as the experience is relevant.


Where is the company located? If you have time constraints, having to ship finished products from overseas may be a deal-breaker. Large differences in time zones can also create communication problems.

Certifications and Associations

What manufacturing standards does the company adhere to? Are they compliant with important industry standards? Are they AS9100 compliant, or merely ISO9001 compliant? The ISO standards are a subset of the AS9100 quality management system. The latter ensures you a higher quality experience from beginning to end.

Industry Focus

CNC machine shops tend to cater to specific industries. This likely stems from both the industry contacts built up over time and the specific toolings and knowledge developed. A shop may focus on more than one industry, especially as they grow. If this is your first foray into CNC machining, searching within your specific industry might help.

Once you’ve gone through those four basic criteria, it’s time to get more detailed in your research.

Do They Maintain Modern Equipment?

Your engineers should be able to tell you what kind of equipment will be required to produce the new product. It could be 3-axis or 5-axis CNC mills, CNC press brakes, CNC lathes, etc. Find out what gear you need, then see which potential vendors can meet those needs.

Do They have a Focus on Quality Control?

Quality control is at the heart of CNC machining. If your new product is complex enough, it will be designed with Geometric Dimensioning and Tolerancing, or GD&T. This system is designed to accommodate the highest levels of precision for today’s designs. It can be used to specify every feature of a part. These parts are usually tested for accuracy on coordinate measuring machines, or CMMs. These incredibly accurate machines are vital to ensure the degree of accuracy many parts require. If your product uses this level of control, you’ll need to make sure the machine shop can handle it with no problem, which brings us to our next factor.

Do They Welcome Complex, High Precision Jobs?

You want to find a machine shop that is not only prepared for your job, but anxious to tackle it. Top quality machine shops invest heavily in the high precision required for complex parts. The challenges presented keep their engineers and machinists at the top of their game so they’re always ready for the next major challenge to walk in the door. They want to press the limits of what is possible in terms of accuracy, and always strive to push the latest technology to its limits.

Do They Provide Engineering Support for Product Design and Planning?

Open and ready communication between your designers and the machine shop’s experts is central to making your product a success. Your people know what the product needs to do – the specs and limits. The machine shop you work with needs to support your designers and help them make the designs as efficient and machine-ready as possible. The shop should handle bringing in the raw material, verifying the quality, and beginning production. They should also handle product inspections at various points during manufacture, as well as the First Article Inspection Report, and subsequent inspections as planned with you. Look for project engineers and experts to be brought in from the beginning.

How Much of the Work is Done In-House?

While farming out certain jobs may not be a deal-breaker, keeping your product in-house does save money. It avoids packaging for transport, transport time, scheduling issues, and additional paperwork incurred by involving subcontractors. If the machine shop can manufacture your part, provide all of the necessary inspections, assemble it with other parts, and undertake surface finishing in-house, you can realize significant cost and time savings.

Can They Meet Price, Time, and other Requirements?

Your company has targets to meet. Once you’ve confirmed that a shop can meet your requirements for accuracy, fit, and finish, can they meet your time goals? Can they do it in your budget? If not, do they have suggestions for changes to the project that can bring the price down or speed up the timeline? An experienced machine shop can help you determine where your plans might have wiggle room to allow you to realize some savings. That’s part of the value of choosing to work with professionals.

In the end, it all comes down to transparency and communication. You want to find an awesome CNC machine shop that has the institutional knowledge and generous spirit to work with you to make your project a reality.