Custom CNC Milling Services
Instant quotes on custom milled metal and plastic parts | Quick-turn prototypes and production parts in days | Free standard shipping on all US orders | International prototype pricing includes tariffs | ISO 9001:2015, ISO 13485, IATF 16949:2016, AS9100D certified. ITAR registered.
High Quality Rapid CNC Milling Service
Xometry integrates seamlessly with thousands of qualified manufacturing partners, including US-based ITAR-registered, AS9100D, ISO 9001, and ISO 13485 certified CNC milling facilities. Our massive network enables us to accommodate almost any milling requirement. We support 3-axis, 4-axis, 5-axis, and right-angle milling capabilities to help you rapidly create designs from simple straight lines to complex geometric shapes.
Xometry offers instant pricing, on-demand lead times, and design-for-manufacturability feedback on custom CNC-milled parts, regardless of industry. Get your instant quote today. The price of milled prototypes includes tariffs and shipping for standard parcels.
Xometry's CNC Machining Materials
Aluminum
Aluminum is a highly versatile CNC machining material known for its excellent strength-to-weight ratio, corrosion resistance, and overall durability. It machines exceptionally well, allowing for high speeds, tight tolerances, and cost-efficient production. Its balance of performance, finish quality, and reliability makes it a go-to choice for a wide range of CNC-machined components.
The following aluminum materials can be found on Xometry's quoting menu:
- Aluminum 2024
- Aluminum 6061
- Aluminum 6063
- Aluminum 7050
- Aluminum 7050
- Aluminum 7075-T6
- Aluminum MIC-6
Brass/Bronze/Copper
Brass, bronze, and copper are known for their excellent machinability, wear resistance, and conductivity. These materials produce smooth finishes, retain fine details, and perform well in applications requiring durability or electrical and thermal efficiency.
Xometry auto-quotes the following brass, bronze, and copper materials:
- Copper 101
- Copper 260 (Brass)
- Copper C110
- Copper C932 (Bronze)
- Copper C360 (Brass)
Garolite
Garolite is a durable composite material offering high strength, excellent electrical insulation, and strong resistance to heat and wear. It machines cleanly and maintains dimensional stability, making it ideal for precision parts where reliability and performance are essential.
Xometry offers multiple grades of Garolite, including:
- Garolite G10 (FR4)
- Garolite G10
- Garolite G11 (FR5)
Plastics
Plastics offer exceptional versatility in CNC machining, providing lightweight strength, chemical resistance, and excellent electrical and thermal insulation. We offer options ranging from general-purpose to high-performance engineering plastics, which enable cost-effective solutions across a wide range of design and performance requirements.
Our machinable plastics include:
- ABS
- Acrylic
- Acetal (POM)
- Delrin 100 (AF)
- Delrin 150
- HDPE
- Nylon 6/6
- Polycarbonate
- PEEK / USP Cass VI TECAPEEK / PEEK GF30
- Polypropylene
- PVC
- UHMW PE
- ULTEM 1000
- ULTEM 2300
Stainless Steel
Stainless steels are valued for their exceptional strength, corrosion resistance, and long-term durability. They deliver reliable performance in demanding environments while maintaining precision, making them well-suited for high-strength, wear-resistant components.
Xometry offers stainless steel alloys such as:
- Nitronic 60
- Stainless Steel 15-5
- Stainless Steel 17-4
- 300 Series Stainless Steel (e.g., 303, 304, 316)
- 400 Series Stainless Steel (e.g., 410, 416, 420, 440C)
Steel
Carbon and tool steels are trusted for their strength, toughness, and versatility. They can be machined to precise tolerances and can be heat-treated for enhanced hardness and wear resistance, making them ideal for durable, high-performance components.
Xometry's steel options include:
- Steel 1018
- Steel 1215
- Steel 4130
- Steel 4140
- Steel 4340
- Steel A36
- Tool Steel A2
- Tool Steel O1
Titanium
Titanium alloys are prized for their exceptional strength-to-weight ratio, corrosion resistance, and biocompatibility. These properties make titanium an ideal material for high-performance components in aerospace, medical, automotive, and other demanding applications where strength, precision, and reliability are crucial.
Xometry can automatically quote:
- Titanium Grade 2
- Titanium Grade 5
Custom Sourced Materials
Xometry offers instant online quotes for a wide range of materials, enabling custom CNC-milled parts. If you do not see the material you are looking for, please choose "Other" under the material drop-down on the quoting page and submit for an expert engineering review once you have specified features, tolerances, inspection needs, and quantities required.
Available Finishes
The finishing option with the quickest turnaround. Parts are left with visible tool marks and are deburred to remove sharp edges, unless otherwise specified. We adhere to a standard surface roughness of 125 μin Ra, unless a different surface roughness requirement is specified.
The part is cleaned, deburred, and placed in an abrasive blaster where surface deposits are removed by applying fine glass beads at high pressure, without damaging the surface. Bead blasted parts will have a matte or satin-like appearance.
Type II creates a corrosion-resistant finish. Parts can be anodized in different colors—clear, black, red, and gold are most common—and are usually associated with aluminum. Type III, also known as hardcoat anodizing, is thicker and creates a wear-resistant layer in addition to the corrosion resistance seen with Type II.
These are treatments that enhance the surface properties of machined parts without significantly altering dimensions. Processes such as chromate conversion, passivation, black oxide, and electropolishing improve corrosion resistance, surface cleanliness, appearance, and in some cases, lubricity or electrical performance.
Metal platings, such as electroless nickel, gold, silver, and zinc, are applied to enhance corrosion resistance, conductivity, wear resistance, and aesthetic appeal. These coatings provide durable, uniform protection while preserving the part’s precision and surface finish.
Powder coat and wet paints provide a durable, protective layer that resists corrosion, wear, and UV damage. They offer a uniform, attractive appearance while preserving the underlying part’s precision and performance.
Ready to get started on your CNC milling quote?
Free shipping available for domestic CNC machining orders ; learn more!
Applications of CNC Milling
Rapid Tooling
Because CNC can be applied to virtually any material, it is perfect for rapid tooling, i.e., creating fixtures or molds.
Rapid Prototyping
The range of materials available, low CNC machining costs per unit, and speed of production makes CNC a great option for prototyping.
End-Use Production
High-quality finish, vast material options and precise tolerances have made CNC a favorable technology for end-use parts.
Advantages of CNC Milling
Using the latest CNC machining capabilities, Xometry produces highly accurate, quick turn parts in as fast as 1 day. Our instant quoting platform can cut days off your RFQ process.
Our CNC milling capabilities offer high-precision tolerances, including sub ±.001" tolerances.
CNC machining processes are perfect for prototype and production parts. Xometry can help you scale from initial prototype and testing phases to production runs of 100,000 parts or more.
Choose from over 50 metal and plastic materials. CNC Machines offer a wide variety of certified materials.
CNC Milling Tolerances & Standards
| Description | General Tolerance or Standard |
|---|---|
Description Maximum Part Size | General Tolerance or Standard Milled parts up to 80” x 48” x 24” (2,032 x 1,219 x 610 mm). |
Description Distance Dimensions | General Tolerance or Standard For features of size (Length, width, height, diameter) and location (position, concentricity, symmetry): ±.005”. |
Description Orientation and Form Dimensions | General Tolerance or Standard ±.005" and angularity of 1/2 degree for parts 0-12". For 24" and beyond, please consult Xometry's Manufacturing Standards. |
Description Standard Tolerances | General Tolerance or Standard Tolerances on metals will be held to ±.005" (±0.127 mm) in accordance with ISO 2768 unless otherwise specified. Plastics and composites are held to ±0.010”. |
Description Precision Tolerances | General Tolerance or Standard Xometry can manufacture and inspect to tight tolerances, including sub ±.001" tolerances, per your drawing specifications and GD&T callouts. |
Description Minimum Feature Size | General Tolerance or Standard 0.020” (0.50 mm). This may vary depending on part geometry and chosen material. |
Description Threads and Tapped Holes | General Tolerance or Standard Xometry can accommodate any standard thread size. We can also machine custom threads; these will require a manual quote review. |
Description Surface Finish | General Tolerance or Standard The standard finish is as-machined with a surface roughness of 125 μin Ra or better. Additional finishing options can be specified when getting a quote. |
Description Edge Condition | General Tolerance or Standard Sharp edges will be broken and deburred by default. Critical edges that must be left sharp should be noted and specified on a print. |
Please check out Xometry's Manufacturing Standards for more information on tolerances per process. Unless we have agreed to other tolerances in your Quote, we will work to achieve and hold the tolerances noted.
Overview: What is CNC Milling?
The Basics Of CNC Mills
CNC mills are automated cutting machines using a rotating spindle-head to cut away unwanted material. CNC milling machines come in a variety of sizes and different axis configurations. This manufacturing process is mainly utilized to cut harder metals but can work with workpiece materials ranging from plastic and aluminum to stainless steel and titanium.
How CNC Milling Works
CNC mills excel at profile cutting harder materials. Like all CNC machines, a CNC mill is controlled with G-Code created through CAM software. The Gg-Code instructs the machine where to move the tool head, how fast to spin the tool, how deep to cut, how to move the workpiece, and other factors relating to speed, feed rate, and coordination. The G-Code complexity depends on how many axes the milling machine has.
Mills can still be used for profile cutting of softer materials, but are not as cost-effective for that use as CNC routers. The main difference between these machines is that with a CNC router the workpiece remains stationary while the router cutting head is directed around the piece, while a CNC mill may move both tool head and workpiece. CNC mills are mainly used in industrial manufacturing, while CNC routing is more common for lower output manufacturing like woodworking.
Types of CNC Mills
3-Axis
The most widely used type of CNC milling machine. The full use of the X, Y, and Z directions makes a 3 Axis CNC mill useful for a wide variety of work.
4-Axis
This type of router allows the machine to rotate on a vertical axis, moving the workpiece to introduce more continuous machining.
5-Axis
These machines have three traditional axes as well as two additional rotary axes. A 5-axis CNC router is, therefore, able to machine 5 sides of a workpiece at in one machine without having to remove the workpiece and reset. The workpiece rotates, and the spindle head is able to also move around the piece. These are larger and more expensive.
Other Benefits Of CNC Mill Machining Processes
CNC milling machines are built for precise manufacturing and repeatability which makes them perfect for rapid prototyping and low-to-high volume production runs. CNC mills can also work with a variety of materials from basic aluminum and plastics to more exotic ones like titanium — making them the ideal machine for almost any job. Learn more about the difference between a mill and a lathe and when milling is the best process to use.
Why Choose Xometry for Custom Milling?
Endless Options
Choose from millions of possible combinations of materials, finishes, tolerances, markings, and certifications for your order.
Easy to Use
Get your parts delivered right to your door without the hassle of sourcing, project management, logistics, or shipping.
Vetted Network
We are ISO 9001:2015, ISO 13485, IATF 16949:2016, and AS9100D certified. Only the top CNC machine shops that apply to become Suppliers make it through our qualification process.
