Online CNC Machining Service for Custom Parts

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

Certifications ISO 9001:2015 | AS9100D | ITAR Registered

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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CNC Machining Materials

Aluminum

Aluminum is a popular choice for machining due to its low density, good mechanical properties, high thermal and electrical conductivity, and resistance to corrosion. Aluminum alloys, such as 6061-T651, 7075-T651, and 2024-T351, are commonly used in CNC machining because they offer a good balance of strength, machinability, and cost.

Learn more about aluminum CNC machining

Brass

Brass is an alloying consisting of both copper and zinc. The gold materials is a weather- and corrosion- resistant metal with tensile strength similar to mild steel. It's also an easy to machine material, so feedrates can remain high and coolant need is minimal.

Learn more about brass CNC machining

Copper

Copper is a metal that is corrosion-resistant, extremely electrically conductive, and highly ductile. Its glossy orange-reddish appearance is instantly recognizable, and the metal looks attractive even when it goes through a natural oxidation process that forms a bluish-green coating called patina in response to its environment. Note, however, that copper weldability is considered moderate to poor.

Learn more about copper CNC machining

Stainless Steel

Stainless steel is well-suited for a wide array of CNC machining projects, due to its excellent machinability and outstanding uniformity. It also has good workability and weldability to match your specific machining needs, as well as high ductility and formability to meet the specification requirements of any project.

Lear more about stainless steel CNC machining

Steel Alloy

Steel Alloy 4140 is a low alloy steel containing chromium, molybdenum, and manganese. It is widely used across numerous industries and is an excellent material choice for machining due to its toughness, high fatigue strength, and abrasion and impact resistance.

Learn more about steel alloy CNC machining.

Steel Mild Low Carbon

Low carbon steel, also known as mild steel, contains up to 0.30% carbon. This gives the material low strength while making it more malleable and ductile compared to high carbon steels.

Titanium

Titanium is a popular material for CNC machining due to its excellent strength-to-weight ratio, corrosion resistance, and biocompatibility. However, titanium presents unique challenges in machining due to its high strength, low thermal conductivity, and tendency to work harden during cutting.

Learn more about titanium CNC machining

Aluminum

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Brass

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Copper

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Stainless Steel

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Steel Alloy

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Steel Mild Low Carbon

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Titanium

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Plastics

ABS
Acetal
CPVC
Delrin
HDPE
LDPE
Nylon
PEEK
PEI
PET
PMMA (Acrylic)
Polycarbonate
Polypropylene
Polystyrene
PPSU
PSU
PTFE
PVC

ABS

ABS is a low-cost engineering plastic that is easy to machine. ABS is an ideal material for structural applications when impact resistance, strength, and stiffness are required. It’s widely used for pre-production prototypes since it has excellent dimensional stability and is easy to paint and glue.

Learn more about ABS CNC machining

Acetal

Delrin 570 is a homopolymer acetal containing 20% glass fiber filler. It has very high stiffness, low warpage, and low creep for superior performance at elevated temperatures.

CPVC

CPVC, also known as Chlorinated Polyvinyl Chloride provides excellent corrosion resistance at elevated temperatures making it ideal for self-supporting constructions where high temperatures are a concern.

Delrin

Delrin, also known as Polyoxymethylene (POM), is a high-performance plastic with numerous advantageous features. Its high stiffness, low friction, and excellent wear resistance make it a popular choice for applications requiring high mechanical strength, such as gears, bushings, and bearings.

With its remarkable combination of properties, Delrin stands out as a versatile and reliable material for a diverse range of applications.

Learn more about Delrin CNC machining

HDPE

HDPE is a high-density polyethylene that is lightweight, has low moisture absorption, is chemical and corrosion resistant, and has high strength. It is great for applications such as orthotic and prosthetic devices, water storage, and tanks.

Learn more about HDPE

LDPE

LDPE is more flexible than HDPE, while still being light-weight and providing chemical and corrosion resistance. It’s extremely flexible making it great for prosthetic devices and thermoformed parts.

Nylon

Nylon is a versatile and widely used material in CNC machining due to its exceptional properties. Its high tensile strength, low coefficient of friction, and resistance to wear and abrasion make it an excellent choice for applications requiring durability and reliability, such as gears, bushings, and bearings. Additionally, nylon's low moisture absorption and good dimensional stability ensure consistent performance even in humid or varying temperature conditions.

Its ease of machining, coupled with its chemical resistance, also makes it suitable for applications in the automotive, aerospace, and medical industries. With its remarkable combination of properties, nylon stands out as a versatile and reliable material for a diverse range of CNC machining applications.

Learn more about nylon CNC machining

PEEK

Using PEEK materials (chemically known as polyetheretherketone) is ideal for a wide spectrum of CNC machining applications where thermal, chemical, and combustion properties are critical to performance.

Whether in a sheet, rod, tube, or film, PEEK is a high-performance material that can be cut to size and used for a variety of CNC machining projects.

Learn more about PEEK CNC machining

PEI

ULTEM is an amorphous thermoplastic polyetherimide (PEI) material that combines exceptional mechanical, thermal, and electrical properties. Natural ULTEM is a translucent amber color. Key attributes include excellent mechanical strength, ability to retain strength at elevated temperatures, high heat resistance, and high stress resistance.

PET

PET, also known as Polyethylene Terephthalate, is a semi-crystalline thermoplastic polyester with excellent wear resistance, low coefficient of friction, high flexural modules, and superior dimensional stability. It it a very versatile option for mechanical and electro-mechanical parts.

PMMA (Acrylic)

Acrylic, also known as polymethyl methacrylate (PMMA), is a versatile plastic material widely used in CNC machining for its remarkable properties. Acrylic's optical clarity, light transmission, and UV resistance make it a popular choice for a wide range of applications, from signage and display products to lenses and lighting fixtures.

With its exceptional combination of optical clarity, machinability, and versatility, acrylic is an excellent choice for CNC machining applications that require precision and aesthetics.

Learn more about acrylic CNC machining

Polycarbonate

Polycarbonate (PC) is an engineering plastic with excellent dimensional stability and good strength and stiffness. It's a go-to material for parts that need clarity and impact strength.

We offer four grades of machined polycarbonate:

Black
Clear
Translucent
20% Glass-Filled

Learn more about polycarbonate CNC machining

Polypropylene

Polypropylene (PP) Copolymer is a common thermoplastic often used for its versatility. It is easy to fabricate, will not crack with vibration or wear, and can also be used in applications that require chemical resistance and/or FDA compliance.

Polystyrene (HIPS)

High Impact Polystyrene (HIPS), is a low cost plastic material that is easy to machine. It is often used for low strength structural applications when impact resistance, machinability, and low cost are required. It is a great material choice for prototyping due to its dimensional stability and ability to paint and glue.

Learn more about High-Impact Polystyrene (HIPS).

PPSU

RADEL R polyphenylsulfone resins offer exceptional hydrolytic stability and toughness that is superior to other commercially available, high-temperature engineering resins. It offers high deflection temperature and outstanding resistance to environmental stress cracking. The polymer is inherently flame retardant, has excellent thermal stability, and good electrical properties.

PSU

PTFE

Polytetrafluoroethylene (PTFE), commonly known by its trade name Teflon, is a versatile and highly desirable material for CNC machining due to its unique properties. It is a type of fluoropolymer and is best known for its non-stick and low-friction properties. This makes it an excellent choice for applications that require a low coefficient of friction, such as bearings, bushings, and seals. PTFE also has excellent chemical resistance, making it ideal for use in harsh environments.

Additionally, PTFE has a wide temperature range, from -200°C to +260°C, which makes it suitable for applications that require extreme temperature resistance. Its electrical insulation properties are also noteworthy, making it useful in electrical components and insulation.

Learn more about PTFE CNC machining

PVC

Polyvinyl Chloride (PVC) is an extremely versatile polymer and used widely across many industries due to its exceptional corrosion resistance, high strength-to-weight ratio, and cost efficiency.

ABS

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Acetal

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CPVC

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Delrin

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HDPE

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LDPE

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Nylon

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PEEK

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PEI

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PET

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PMMA (Acrylic)

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Polycarbonate

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Polypropylene

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Polystyrene

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PPSU

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PSU

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PTFE

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PVC

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Tolerances for CNC Machining

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

Standard
Metric

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	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

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)

Coating and Plating Options:

Anodizing
Chromate coating
Powder coating

Learn more about post-processing options for CNC machining.

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.

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.

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Get an Instant CNC Machining 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.

View a Sample Quote