CNC Machining Part

Online CNC Machining Service for Custom Parts

Machined prototypes and production parts in as fast as 1 day. Request an online quote today.

ISO 9001:2015 | AS9100D | ITAR Registered

Choose the right machining service for your product development needs. 

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CNC Machining Capabilities

CNC Milling

CNC milling is a subtractive manufacturing process that uses 3-axis milling and 5-axis indexed milling processes to cut solid plastic and metal blocks into final parts.

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CNC Turning

CNC turning with live tooling combines both lathe and mill capabilities to machine parts with cylindrical features from metal rod stock.

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Protolabs Network

Our manufacturing network provides advanced CNC machining capabilities like tighter tolerances, volume pricing, and anodizing options.

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CNC Machining Materials





Looking for additional metals like Inconel, Invar, or magnesium? How about plastic like fiber epoxy or Garolite? Try our digital network at Hubs.

NASA Generative Design X Quick-Turn Manufacturing

Learn how we partnered with NASA to crowdsource the generative design of a moon exploration tool on an ultra-quick timeline. 


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Factory vs. Network

We offer a range of capabilities through our in-house digital factories at Protolabs along with our digital network of manufacturers at Hubs. If speed is essential, our factory capabilities have you covered, but if you're in need of advanced capabilities and have more flexibility in your schedule, try our network.


Factory Capabilities

Network Capabilities

Maximum Part Size 22 in. x 14 in. x 3.75 in. (559mm x 356mm x 95.3mm) 25.5 in. x 25.5 in. x 11.8 in. (650mm x 650mm x 300mm)
Minimum Part Size 0.25 in. x 0.25 in (6.35mm x 6.35mm) 0.019 in. (0.50mm)
Tolerances +/- 0.005 in. (+/- 0.13mm) +/-0.001 in. (0.020mm)
Radii Sharp inside corners on a part will be radiused (rounded) as a natural result of the CNC machining process.

Plastic and soft metals: Minimum width of 0.018 in. (0.457mm), depth of 0.0118 in. (0.3mm). Example text size would be 16 point Arial Rounded MT font.

Hard metals: Minimum width of 0.033 in. (0.838mm) and depth of 0.0118 in. (0.3mm). Example text size would be 22 point Arial Rounded MT font.

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Note: Maximum part size varies by material. View this table to see a complete listing of our maximum part sizes.


Factory Capabilities

Network Capabilities

Maximum Dimensions Diameter 3.95 in. (100.33mm) 17 in. (431mm)
Length 9 in. (228.6mm) 39 in. (990mm)
Minimum Dimensions Diameter 0.16 in. (4.07mm) 0.039 in. (1mm)
Length 0.05 in. (1.27mm) 0.019 in. (0.5mm)
Wall Thickness 0.020 in. (0.51mm) 0.019 in. (0.5mm)
Angle 30° Below 90°
Tolerances +/- 0.005 in. (+/- 0.13mm) ±0.001 in. (0.020mm)
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Note: Small features may be allowed, but the diameter in any region should not be less than 0.030 in. (0.76mm). Sharp conical points are allowed; angles should be greater than 30 degrees. Walls thinner than 0.020 in. (0.5mm) typically do not survive the machining process.

Finished Parts in as Fast as 4 days!

Get machined parts anodized and chromate plated with our quick-turn finishing option. Eligible materials include aluminum 6061/6082 and 7075. Start your next machining project today.

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Why Choose Us for Custom CNC Machining?

Fast and Reliable Delivery

Iterate part designs quickly and accelerate product development with quick-turn parts. Our automated design analysis will help spot any difficult to machine features before your design is sent to the manufacturing floor and save you from costly reworks further down the product development cycle.

Manufacturing Analysis and Online Quotes

When you upload your 3D CAD file to request a quote, we'll analyze your part geometry to identify any features that may be difficult to machine such as tall, thin walls or holes that cannot be threaded.

Domestic Production and Support

Work with a trusted U.S.-based manufacturer and eliminate the risk of sending parts overseas. You can also call or email us at any time and we'll help with ordering parts, design feedback, material recommendations, and answer any questions.

Infinite Capacity

Eliminate downtime spent waiting for parts and safeguard in-house machining with on-demand relief and infinite manufacturing capacity.

Material Selection

We stock more than 30 engineering-grade plastic and metal materials that are suitable for various part applications and industries. Materials range from plastics like ABS, polycarbonate, nylon, and PEEK to aluminum, stainless steel, platinum, and copper.

Advanced Capabilities

Get anodizing, tighter tolerances, and volume pricing options through our network of manufacturers at Hubs. You'll find plating (black oxide, nickel), anodizing (Type II, Type III), and chromate coating in larger part quantities; tolerances down to ±0.001 in. (0.020mm); and cost-efficient machined parts at higher volumes to lower piece-part price.

What is CNC Machining and How Does it Work?

CNC machining is an automated manufacturing process that transforms a solid block or rod of material into a part using end mills. The end mills are controlled by software (G-code) which references a 3D CAD model to reduce the stock material into a desired geometry. Parts can be manufactured relatively quickly due to the level of automation. 

There are many types of CNC machines, which include CNC milling and CNC turning. CNC machining is a suitable manufacturing process for one-off prototypes or custom components as well as mid-volume production quantities.

Check out our complete guide to CNC machining to learn more


Advantages of CNC Machining

The subtractive process of CNC machining provides multiple benefits for both prototyping and production parts.

  • Precision and repeatability
  • Tight tolerances
  • Production-grade materials
  • Quick-turn parts within 1 day
  • Lower piece-part price at higher quantities
  • Robust post-processing to improve cosmetics and material properties

CNC Machining Applications

CNC machining is widely used throughout the aerospace, medical, automotive industries for its ability to rapidly manufacture precise parts in production-grade materials. Typical CNC parts, include:

  • Housings and enclosures
  • Brackets
  • Fixtures for manufacturing
  • Gears and bearings
  • Internal mechanical components
  • Medical instrumentation

If you have any issues getting your guide, click here to download.

CNC Machining Design Guide

In this guide to CNC machining, you'll learn how to create efficient, manufacturable metal and plastic parts for prototyping and production.

Surface Finish and Post-Processing Options

Protolabs offers a variety of CNC machining surface finishing options to meet your part requirements. More advanced coating and plating options are also available. 

Surface Finish Options: 

  • Edges broken with tool marks visible
  • Edges broken with light bead blasting
  • Sharp edges (tool marks visible)
sample of chromate plating

Coating and Plating Options: 

  • Anodizing 
  • Chromate coating
  • Powder coating


Learn more about post-processing options for CNC machining.


Tour Our Machine Shop (Virtually)

Take a quick tour through our 215,000 sq. ft. CNC machining facility in Minnesota to see how we manufacture parts in as fast as 24 hours.


What's in an Online CNC Quote?

Upload a 3D CAD file of your machined part and within a few hours we'll send you manufacturing analysis and an interactive quote. Within your quote you can modify materials and quantities and see pricing updates in real-time. Additionally, within your manufacturing analysis, you can assign threading with a click of your mouse.

Tolerances for CNC Machining

We offer a wide range of tolerances for CNC machined parts to fit your project priorities. 

  Tolerances Lead Times
Automated Factory +/- 0.005 in. 1-3 days
Traditional Factory +/-0.002 in. 4-15 days
Network +/-0.001 in. 5-20+ days
  Tolerances Lead Times
Automated Factory +/- 0.13mm 1-3 days
Traditional Factory +/- 0.0508mm 4-15 days
Network +/- 0.020mm 5-20+ days

CNC Machining FAQs

How much does CNC machining cost?
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Prices start around $65, but vary based on complexity, quantity and lead time. The best way to find out is to submit a 3D CAD model and get an interactive quote with design for manufacturability (DFM) feedback. Because we use proprietary software and automated fixturing processes, there are no up front non-recurring engineering (NRE) costs. This makes purchasing quantities as low as 1 to 200 parts cost effective. Prices compared to 3D printing are comparable to somewhat higher, but machining offers improved material properties and surfaces.

What types of threading options are available?
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We offer UNF, UNC, and metric threads for machining along with coil and key inserts (but do not supply or install the inserts). These are available on both milled or turned CNC parts. View this page to see our complete threading options.

What is the maximum part size for CNC machining?
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Maximum part size will vary based on your selected material. Our largest part size offered is 22 in. x 14 in. x 3.75 in. (559mm x 356mm x 95.25mm) and is available in Aluminum 6061 and 7075. View this table to see maximum dimensions by material.



Where can I learn more about CNC design?
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We have a variety of resources on CNC machining and how to design parts for the process. Here are some of our favorites:

Additional Links and Resources