CNC Machining

CNC Prototype Machining

At Mountain Machine Works, we can help your OEM manufacturing plant take a product from prototype to production all under the same roof.

Offering skilled CNC prototype machining and production manufacturing services, our qualified professionals can help your team flesh out a new or re-engineered product line to create higher-quality parts at a lower cost.

The Top Choice: CNC Prototype Machining & Production Manufacturing

Trusted by many established companies, Mountain Machine Works is the top choice for manufacturers looking to improve their product lines. With precision machining technology backed by an experienced team of process engineers, we can handle all types of materials and finishes.

Our CNC prototype machining process ensures that all products are of the highest quality. Clean, well-packaged, and ready to be used, everything that comes out of our shop is held to a high standard of excellence and quality assurance.

Talk to a rep today and discover how we can help you prototype your production line and bring it to manufacture in as little as 3-5 weeks.

Large Parts Machining

Few precision prototyping companies are equipped with the machines to handle large part machining, but that doesn’t remove the need from the industry.

At Mountain Machine Works, our large part machining team specializes in providing quality parts at an affordable rate.

Our job is to maximize your manufacturing efficiency, whether you’re re-engineering an existing line or prototyping a new product line.

We can machine parts up to 59” x 120”.

CNC Hard Milling

Hard milling is a process that can be used to create parts that have a certain Rockwell hardness. This represents how resistant the part is to penetration and permanent deformation from another material.

The hard milling process differs from normal machining because it requires special equipment and understanding of material hardness.

Originally, hard milling was used to apply changes or additional machining to parts that had been reinforced through heat treating. It eventually became an individual process for the reasons below:

  • The need for mold and die components that can be made quickly (faster time to market).
  • The cost and time commitment required for EDMing, surface grinding, and jig grinding.
  • Newer pre-hardened materials such as P20, H13, and 4140 are available.
  • CAD/CAM and 3D machining are getting more sophisticated.
  • There have been big improvements in machines, machine tools (cutters), and tool holding devices.
  • The need to make new or replacement tooling components, reduce lead times, and improve surface finishes is increasing.

Mountain Machine Works has the capability to machine up to 50-55 Rc (Rockwell C).

CNC Hard Milling

Thin Wall Turning

Thin wall turning is one of the most challenging processes in CNC prototype and production machining.

One of the most common difficulties when machining a product that must be turned is inaccuracy in the final product. Most of these products, like thin-wall tubing or pressure vessels, require a different machining approach that few shops have the know-how to machine. Because of the difficulty of manufacturing this type of product, costs from product loss and production time can be high.

Fortunately, Mountain Machine Works has a thin wall turning process that enables us to achieve higher degrees of precision and speed the production time up, reducing loss in the overall product run. We accomplish this through specialty tooling and fixturing proprietary to our process that we have developed over the last 40 years.

Accurate thin wall CNC machining is accomplished at Mountain Machine Works through specialty tooling and fixturing proprietary to our process.

Aluminum Parts

Shaft Machining

Shaft machining is a critical part of several industry sectors such as aerospace, pharmaceutical, power generation, military, mining, and heavy equipment services.

This manufacturing process can be difficult to manage as these shafts must be able to withstand demanding tolerances no matter the metal type.

Types of shaft machining our shop is capable of producing include: eccentric, impeller, journal, main, output, pump, roll, and rotor shafts.

Want to learn more about our shaft machining processes? Get in touch today to discuss your project’s prototyping and product manufacturing needs.

Why Choose Us for Your CNC Prototype Machining?

CNC prototype machining is a great way to keep your production line flexible during the engineering phase.

Specializing in OEM prototyping and manufacturing, Mountain Machine Works understands the importance of tight tolerance precision machining.

With CNC prototype machining from Mountain Machine Works, products go into the manufacturing process at a higher quality and prevent issues typically encountered by lower-cost production manufacturers . Ultimately, it saves your company money and the landed cost to the customer is lower.

Serving the northeastern United States and beyond, our team will work with you to develop a prototype, seamlessly move your prototype to production, while handling the entire project under one roof.

This keeps your production costs low and allows you to work with a single point of contact. Meanwhile, your product line is moved further down the funnel by a team that truly understands the engineering and development of the product.

Reduce Costs Before Production

While prototyping is considered an up-front expense when creating or re-engineering product lines, it greatly reduces the long-term costs of the project and keeps overall turnaround short.

CNC prototyping features a range of benefits, such as ensuring no quality issues arise during manufacturing that would otherwise delay production. By preventing delays and quality control issues that arise during manufacturing, product lines can be re-established in short order.

Parts can also be customized completely to OEM specifications within a fine range of precision, preventing the need for additional, post-production quality assurance and product loss from low-precision manufacturing practices.
Savings from these associated costs are not commonly calculated into the final ROI, but make the manufacturing process faster and more cost-effective, improving the company’s bottom line per unit.

Dependable Turnaround Time: Machined Parts on Your Schedule

Your company is on a timeline. Every moment that a product line is delayed is another moment that your company is losing profits and your bottom line is shrinking. We specialize in the prototyping and production of high-quality parts with a tight tolerance and efficient design that keeps profits as high as possible, and costs lowered for the landed consumer.

We strive to keep your team involved at every phase of the project so you can make informed decisions about your production timeline. During the project lifecycle, we’ll work with your engineering teams to ensure the product is precise and repeatable in the manufacturing process. No matter what your schedule is for the product line, we can work with you to determine a timeline for delivering quality machined parts in no time.

The typical turnaround for putting a product through prototyping at Mountain Machine Works can be as little as 3-5 weeks. During this time, you will work with a rep every step of the way to make sure the product is perfect to your specifications and meets your quality assurance standards.


We don’t let quality issues slide, keeping your team informed about the prototyping and production phase, and providing updates on overall turnaround time and production run details every step of the way.

You will work with a single project manager throughout your partnership with Mountain Machine Works, handling PO from start to finish. From ordering raw materials to setting up the shipping of your final product, you will have access to a point of contact who is deeply involved with your products’ process and able to answer any technical questions.

Who Do We Work With?

Many of our contracts come from established OEM suppliers looking to prototype or re-engineer a new product.

During this prototyping phase, we manufacture small runs and work with your engineers to further develop the parts. Each run is between 20-100 pieces, up to 10,000 depending on the product.

This allows us to also fine-tune the quality assurance process and minimize product loss when your product moves to manufacturing.

Schedule Your Professional Machinability Review

We understand how much of a difference small, iterative improvements make on your bottom line, which is why we do our best to ensure every new or re-engineered product line undergoes a professional machinability review to save costs. We take quality issues very seriously, and it shows from the very beginning.

During the machinability review, our team will work with your engineers to discuss the part’s necessary tolerances and specifications, helping your team design a part that is cheaper and easier for the manufacturer, while also improving product design or quality.

You deserve a prototyping and manufacturing company that can take your product from start to finish under a single roof. As your one-stop shop for precision machining, we are dedicated to building a client relationship with your company and guiding the project every step of the way. Throughout the machinability review process, our team will be testing your products for ways to make it through manufacturing easier and keep turnaround time low.

OEM Manufacturing and Prototyping Made Easy

Whether your team is working on a new product line, or re-engineering an existing one, we can help you create an efficient and cost-effective solution that improves the final product.

We guide you through every step of the process and work with your team to ensure that the products we prototype are up to OEM guidelines and specifications with a high degree of precision.

For your next project that requires skilled CNC prototype machining, contact Mountain Machine Works. Our shop is located in Auburn, ME, and we service the whole northeast region of the United States, as far as Pennsylvania, New York, and beyond.

CNC Machining Materials

Our shop is set up to handle a range of materials and finishes, including more difficult materials that aren’t commonly handled by precision machining shops.

Materials that we can handle include:

Aluminum CNC Machining


Our team can work with any type of machinable metal, even difficult exotic materials such as titanium and molybdenum. We also work well with aluminum, stainless steel, cast iron, and ductile iron.

CNC Machining Plastic


Set up with plastic machining technology, we can handle a range of plastic types. ABS, PC, ABS+PC, PP, PS, POM, PMMA, PAGF30, PCGF30, DHPE, HDPE, PPS, PEEK, and Teflon.

Surface Treatments for CNC Machined Parts

We can provide a variety of finishes based on the material type and product need.


This type of finish is cost-efficient for aspect parts and inner components that don’t affect the products’ overall appearance.

Black Nitride

Black nitride finish is applied to CNC machined parts to increase their resistance to corrosion and wear. The finish is smooth and has a matte black color.

Heat Treat

Heat treatment is a finish that is applied to CNC machined parts in order to improve their strength and durability. It involves heating parts to a certain temperature and then cooling them down slowly. This process helps to harden the part's surface and make it more resistant to wear and tear.

Electrolysis Nickel

Nickel electroplating is a process that is used to deposit a thin layer of nickel onto a part’s surface. It provides a smooth, shiny surface that is corrosion-resistant. Nickel electroplating also helps to protect the underlying metal from oxidation and staining.

Bead Blasted

Bead-blasting creates a range of desired roughness based on the density of beads and leaves the product with a matte finish.


Creates a corrosion-resistant finish for products that must feature wear resistance and durability. Anodizing provides the option for a range of colors from clear to blue and red.

Powder Coating

Powder coating is one of the most common finish types as it is versatile, cost-effective, and provides a wide range of color options. The finished part is coated in a colored powder and baked for a strong, durable finish that is corrosion resistant.

Serving the northeastern region from Maine to Pennsylvania, we are dedicated to our customers and work to make every product more efficient than the last.

Get in touch today to learn more about our range of material and finish options, or to get a quote on your project.

Machining Tight Tolerance Parts

Tight tolerances are a critical component of OEM manufacturing.

You need your parts to be accurate and secure, so they last longer with higher resistance to damage and wear. You deserve to work with a company that understands these needs and can work directly with your engineers to create a solution that lowers overall production costs, lowers landed customer costs, and raises overall product quality.

At Mountain Machine Works, our team works with precision CNC engineering, helping you achieve tolerances as tight as ±0.0002” or ±0.005 mm. These tight tolerances are applicable to any machined part, whether you need CNC milling, shaft machining, or large parts machining.

We focus on making good parts so you can sell quality products. Talk to one of our sales representatives today to learn more about our processes and discover how we can help you take your product from prototype to production line.

Tight Tolerance Parts

CNC Machining FAQ

CNC machining costs vary based on the product you are producing or prototyping. At Mountain Machine Works, we specialize in CNC prototyping as well as full-scale production machining, all under one roof.

This means that not only is the project easier for your team, but product quality is improved as our engineers familiarize themselves with your custom OEM products over the prototyping phase and know the production process inside and out.

It’s our job to create a seamless prototype-to-production product for your company, and we take pride in providing the highest quality services across the Northeast. We focus on making good parts so you can make good products that end up in your customers’ hands.

For an official quote regarding your CNC machining project, get in touch with our sales representatives today. We are looking forward to discussing your project and partnering with you to create excellent end products.

Yes, we specialize in tight tolerance CNC parts as required by OEM production lines.

Our experienced team of CNC operators works with the individual product in the prototyping stage to keep manufacturing as efficient as possible with the latest machining technology and quality assurance.

Large part machining can be difficult to source across the northeast because many shops across New England are prohibitively expensive, making the landed customer cost much higher than is practical for many established companies.

By minimizing machining waste and working with a wide range of materials to provide machined parts at a fraction of the cost of other manufacturers, our team can handle machining parts up to 59” x 120” for your production line.

Let’s Discuss Your Project

Are you working on a new product line or re-engineering your manufacturing processes for faster turnaround time, better end-product appearance, and lowered production costs?

At Mountain Machine Works, we provide you with the ability to keep everything under one roof. As a one-stop shop from prototype to production, our team partners with you for the long run, ensuring your products hold up to rigid OEM restrictions and guidelines.

With our prototyping and manufacturing processes, you don’t need to deal with issues created by lower quality cost-prohibitive products. We provide all the solutions in-house so that your end product is cost-efficient and quality-assured, all with the shortest turnaround time in the region.

We work with you to determine the best prototype solutions and guide your project from start to finish. Discover how we can help you today and get in touch with our team today. We are looking forward to helping you with your project.

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