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On-demand Custom CNC Machining Services

Online CNC machining service for rapid prototypes and production parts in metals or plastics. Get instant quotes today, and order your custom CNC machined parts at a better price.
  • Rapid Prototyping
  • Flexible Low-Volume Manufacturing
  • Precision Parts with Tight Tolerances
  • Fast Delivery – As Quick as 5 Days
  • All uploads are secure and confidential.
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  • Response within 10 hours
  • Secure file upload
  • Delivery in as fast as 5 days
Iso

ISO

9001:2015 Certified
Machine

+

CNC Machines
Material

+

Plastic & metal materials
Part

K+

CNC parts made monthly
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Custom CNC Machining Services for Metal and Plastic Parts

3ERP is an ISO 9001:2015 certified manufacturer providing high-quality CNC machining services for custom parts. Our in-house capabilities include 3-, 4-, and 5-axis CNC milling, as well as CNC turning, routing, EDM machining, drilling, and precision grinding. These processes are all capable of achieving tolerances down to ±0.01 mm.

From rapid prototyping to full-scale production, our machine shops can make any custom design. We specialize in rapid machining, prototype CNC machining, and both high- and low-volume manufacturing. Additionally, we provide a wide variety of surface finishes, including anodizing, powder coating, electroplating, and more, to enhance durability and aesthetic appeal for machined parts.

Whether you are a startup, an SME, or an OEM, 3ERP is your trusted partner for outsourcing CNC services. Submit your CAD files and drawings to receive a prompt quote.

Our CNC Machining
Capabilities

We are always ready for the challenges of tight tolerances and complex CNC machined parts. Try out our precision CNC machining services and become our next satisfied customer.

CNC Milling Service

3ERP offers custom CNC milling services using 5-axis machines, along with several 3- and 4-axis mills. We deliver precision CNC machining for complex metal and plastic parts with precision tolerances. Our CNC milling capabilities are ideal for:
  • Mold and die making
  • Prototypes and production parts
  • High-performance and engineering-critical applications

CNC Turning Service

Our CNC turning services use high-performance lathes, turning centers, and mill-turn machines to produce precision-machined cylindrical components, such as shafts, bushings, and worm gears. With live tooling, we enable multi-axis machining in a single setup. These services support:
  • Rapid prototypes and production volumes
  • Tight-tolerance round parts
  • Multi-axis turning with milled features

EDM & Wire-Cut Service

Our precision Wire EDM (Electrical Discharge Machining) uses conductive wire—such as copper, graphite, or molybdenum—to cut complex shapes with tight tolerances, sharp corners, and intricate undercuts. This non-contact process is ideal for:
  • Mold and die tooling
  • High-precision prototypes and production parts
  • Hardened steels and exotic alloys

CNC Grinding Service

For ultra-flat surfaces and precise OD/ID tolerances down to ±0.0002″ (±0.005 mm), our CNC grinding capabilities ensure exceptional accuracy and surface finish. This service is ideal for:
  • High-precision metal components
  • Post-machining surface refinement
  • Tight-tolerance OD/ID applications

Swiss Machining Service

Swiss machining efficiently produces complex, slender parts by moving both the tooling and workpiece, minimizing deformation compared to traditional CNC lathes. This process is ideal for:
  • High-precision shafts and pins
  • Medical, aerospace, and electronics components
  • Tight-tolerance small-diameter parts

CNC Routing Service

Our affordable CNC routing capabilities are ideal for cutting prototypes and parts made from soft materials such as EPS foam, EVA, and wood. This service complements standard CNC milling and is perfect for:
  • Lightweight structural models and mockups
  • Foam and plastic packaging prototypes
  • Custom wood or composite components

Why Choose 3ERP?

Compared with other CNC machining companies, here are the top four reasons why you should use our custom CNC machining services.

Fully Equipped CNC Machine Shops

With in-house advanced manufacturing and inspection equipment, which includes HAAS CNC mills and lathes, Hexagon CMMs, and Olympus XRF analyzers. We can guarantee your CNC parts are made in the correct material and dimension.

Instant Quotes and Expert Engineer Feedback

We provide quotes within 24 hours of receiving your 3D CAD files. Our expert engineers analyze part geometry to identify challenging features, such as tall, thin walls or unthreadable holes, and provide actionable feedback based on their extensive CNC machining experience.

End-to-End Quality Assurance

We ensure every CNC part meets specifications through full inspection, including First Article Inspection (FAI), CMM checks, Material Test Reports (MTR), surface finish, and dimensional tolerance verification, delivering defect-free parts before shipping.

Fast Turnaround and Global Delivery

With a trusted manufacturing network, we provide fast-turn CNC machining service. We offer global shipping to key markets including North America and Europe, delivering your parts quickly and reliably wherever you are.

Order Processing

Get 3-day standard lead times on simple parts between 10 mm x 10 mm and 200 mm x 200 mm. Upload your part to see if it’s eligible.
01

Upload CAD file

Submit CAD/3D files for your part, with specs, tolerances, and notes to ensure accurate production.
02

DFM Review & Quote

Engineering reviews manufacturability, provides feedback, a quote, and estimated lead time, usually within 24 h.
03

Production & QC

Upon approval, parts are machined per ISO 9001:2015, with in-process and final inspections; reports available on request.
04

Global Delivery

Upon confirmation, parts are safely packaged and shipped globally.

Put your parts into production today

All information and uploads are secure and confidential.
Upload
Quote
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Supports:
  • STEP
  • STP
  • SLDPRT
  • IPT
  • PRT
  • SAT
  • IGES
  • IGS
  • CATPART
  • X_T
  • OBJ
  • STL

One-Stop CNC Machining Parts Supplier

CNC machining is an ideal manufacturing process whether you need a few parts or 10000+ units as end-used production parts. Here are the custom CNC services available at 3ERP.

Rapid Prototyping

3ERP delivers quick turn prototype parts in just days to help engineers, designers, and product developers validate designs accurately.
  • Instant online quote
  • Instant DFM feedback
  • Excellent quality
  • Short lead time

Low-volume Manufacturing

CNC machining is a cost-efficient way to make certain types of parts in small volume or medium quantity. For example, 100 pieces to 1000 pieces.
  • Lower cost
  • Production-level quality
  • Short lead time
  • Test out the market before investment

End-use Production

CNC machines and robots are an excellent combination for manufacturing, whether for small batches or large volumes.
  • Experienced engineers for DFM optimization
  • A professional PM working in your time zone
  • First Article Inspection
  • Guaranteed consistent quality
Case Studies

CNC Success Stories & Testimonials

Here are some of the CNC machining projects that we have done for our customers. And the happiness they would like to share when they receive the parts.

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Front Upright Cnc Machining 06
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Formula SAE Racing Front Uprights
  • Material: Aluminum 7075-T6
  • Process: 5-axis CNC Machining
  • Surface Finish: As Machined
Challenges

The uprights feature complex geometries with deep pockets and thin-walled sections. The key challenge was maintaining tight bearing bore tolerances (±0.01 mm) while preventing vibration and deformation during machining.

Our Solution

3ERP applied single-setup 5-axis CNC machining to complete all critical features in one clamping, eliminating re-fixturing errors.

High-precision drilling, boring, and rigid tapping ensured accurate hole geometry and reliable threads, while in-process and final inspections verified all tolerances.

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CNC Machinging
Custom Center-Lock Wheel Hubs
  • Material: Aluminum 7075-T6
  • Process: CNC Turning + 5-axis CNC Machining
  • Surface Finish: As Machined
Challenges

The wheel hubs required extreme concentricity, thin-wall strength, and deep internal machining, all under a tight motorsports schedule.

Our Solution

3ERP used precision CNC turning, custom 5-axis fixtures, and dynamic milling strategies to achieve micron-level accuracy, lightweight structures, and race-ready reliability.

Feedback
Thanks to 3ERP’s 5-axis machining capabilities, we’re able to push the limits on our uprights and wheel package designs for maximum performance.
Brown Formula Racing
Master cylinder
Master cylinder

Master Cylinder Prototypes for Braking System.

  • Material: Aluminum 7075 T651
  • Quantity: 4
Challenges

Tolerance of the deep cavity is +/-0.02mm, in the meantime, the roughness must be Ra0.1. The small channels are multiple directions, tight tolerance to ensure the rate of flow.

Our Solution

Use 5 axis milling machine to minimize the machining step. Special drilling tool for the 0.5mm holes. Reamer to achieve high gloss inner surface.

Feedback
We received the cylinders yesterday. Our engineers have inspected them and assembled them with other components. All goes well. Thank you so much for such a great job. Please send our thanks to your projection team. We are planning to make 5 more pieces in a different design few days later. Will shot you an email when the design is ready. Have a nice day!
Ryan Growel
Car model
Car model
Car Model
  • Material: PMMA
  • Quantity: 1
  • Finishes: High Gloss Polished
Challenges

The geometry of this model is complex. Some of the joint lines are almost flat.
Our customer had this model made by 3D printing which is not as good as expected.

Our Solution

Use our precision 5-axis CNC milling machine to get the diamond surface milled as fine as possible. That we can avoid sanding and polishing it directly after machining.

Feedback
Hey folks, thank you very much for bringing our design into reality! We really appreciate that your team guided us to the right path. CNC machining is indeed a better way than 3D printing to make this model.
Kyndel Wilson

CNC Machining Materials

We offer a wide range of engineering-grade plastic and metal materials, including aluminum, brass, steel, stainless steel, ABS plastic, glass, and wood. If your desired material is not listed in our stock, please specify the required features, tolerances, inspection requirements, and quantities so our engineering team can review your request.

Aluminum

Aluminum

Brass

Brass

Copper

Copper

Steel

Steel

Stainless Steel

Stainless Steel

Bronze

Bronze

Titanium

Titanium

Magnesium

Magnesium

Zinc

Zinc

Inconel

Inconel

Invar

Invar

ABS

Abs

PMMA (Acrylic)

Pmma (acrylic)

PC

Pc

POM/Delrin

Pom, Delrin

PC GF30

Pc Gf30

PA(Nylon)

Pa

PC+ABS

Pc+abs

PA GF30

Pa Gf30

PP GF30

Pp Gf30

PP

Pp

PTFE (Teflon)

Ptfe (teflon)

PEI

Pei

PS

Ps

PPS

Pps

PE

Pe

PPSU

Ppsu

PET

Pet

PEEK

Peek

LDPE

Ldpe

G-10/FR4

G 10 Fr4

HDPE

Hdpe

PVC

Pvc

Wood

Wood

Glass

Glass

Stone

Stone

Ceramics

Ceramic
Aluminum
Aluminum offers excellent machinability, corrosion resistance, and durability, making it ideal for various applications, such as aerospace, automotive parts, and outdoor components.
Color
Alloys
Aluminium 7075-T651 | 3.4365 | 76528 | AlZn5.5MgCu Aluminium 6082-T651 | 3.2315 | 64430 | AlSi1MgMn Aluminium 6060 | 3.3206 | AlMgSi Aluminium 5052 | EN AW-5052 | 3.3523 | AlMg2,5 Aluminium 2017 | 3.1325 | 24530 | AlCu4MgSi
Available Finish
As machined, Anodizing, Powder coating, Electroplating, Painting, Sand blasting, Polishing
Price
$$
Lead Time
About 5 business days
Brass
Brass offers excellent machinability, a strong strength-to-weight ratio, corrosion resistance, and high conductivity, making it ideal for industrial applications requiring durability and precision.
Color
Alloys
H59, H62, C260, C360
Available Finish
As machined, Polishing, Sand blasting, Tumbling, Electropolish, Alodine, Heat treatment, Black oxidize, Electroless nickel, Chrome plating, Brushed finish
Price
$$$
Lead Time
About 5 business days
Copper
Copper is an efficient heat conductor with superior malleability, good corrosion resistance, and antimicrobial properties. It is ideal for electrical wiring, plumbing, and heat exchangers.
Color
Alloys
C11000, C10100, C10200
Available Finish
As machined, Polishing, Sand blasting, Tumbling, Electropolish, Alodine, Heat treatment, Black oxidize, Electroless nickel, Chrome plating, Brushed finish
Price
$$$
Lead Time
About 5 business days
Steel
Steel is a strong, versatile material with high tensile strength, ideal for structural components. It has various subtypes for specific applications.
Color
Alloys
Structured Steel, Mold Steel, Alloy Steel, Tool Steel, Bearing Steel, Carbon Steel
Available Finish
As machined, Electroplating, Passivation, Powder coating
Price
$$$
Lead Time
About 7 days
Stainless Steel
Stainless steel is a corrosion-resistant alloy of steel, chromium, and nickel. It’s ideal for kitchen appliances, medical equipment, and automotive parts.
Color
Alloys
Stainless steel 416 | 1.4005 | X12CrS13
Stainless steel 15-5 | 1.4545 | X5CrNiCu15-5
Stainless steel 301 | 1.4310 | X10CrNi18-8
Stainless steel 430 | 1.4016 | X6Cr17
Stainless steel 440C | 1.4125 | X105CrMo17
Stainless steel 420 | 1.4028 | X30Cr13
Stainless steel 304/304L | 1.4301/1.4307 | X5CrNi18-10/X2CrNi18-9
Stainless steel 2205 Duplex | 1.4462 | 2205 | X2CrNiMoN 22-5-3
Stainless Steel 17-4 PH | 1.4542 | X5CrNiCuNb16-4 - Annealed state
Stainless steel 303 | 1.4305 | X8CrNiS18-9
Stainless steel 316/316L | 1.4401/1.4404 | X5CrNiMo17-12-2/X2CrNiMo17-12-2
Available Finish
As machined, Electroplating, Passivation, Powder coating
Price
$$$
Lead Time
About 7 business days
Bronze
Bronze, an alloy of copper and tin, offers excellent durability and corrosion resistance, making it ideal for intricate, heavy-duty components and applications requiring strength.
Color
Alloys
C64200, C93200
Available Finish
As machined, Polishing, Sand blasting, Tumbling, Electropolish, Alodine, Heat treatment, Black oxidize, Electroless nickle, Chrome plating, Powder coating, Brushed finish
Price
$$$
Lead Time
About 5 business days
Titanium
Titanium offers a high strength-to-weight ratio, low thermal expansion, excellent corrosion resistance, and is biocompatible, making it ideal for aerospace, medical implants, and precision machining.
Color
Alloys
Titanium Grade 5 | 3.7164 | Ti6Al4V
Titanium Grade 2 | 3.7035
Titanium Grade 1 | 3.7025
Available Finish
As machined, Polishing, Sand Blasting, Tumbling, Electropolish, Alodine, Anodizing, Electroless nickel, Painting, Powder coating, Brushed finish
Price
$$$$$
Lead Time
About 8 business days
Magnesium
Magnesium is the lightest structural metal with a high strength-to-weight ratio, good machinability, and excellent vibration damping, ideal for lightweight applications.
Color
Alloys
AZ31B, AZ91D, AZ61B, ZK61M, MB15-RE
Available Finish
As machined, Polishing, Sand Blasting, Tumbling, Alodine, Heat treatment, Anodizing, Teflon coating, Electroless nickel, Painting, Powder coating, Electrophoresis
Price
$$$$$
Lead Time
About 8 business days
Zinc
Zinc is a corrosion-resistant metal often used for galvanizing steel, die casting, and making batteries, automotive parts, and hardware due to its durability and low cost.
Color
Alloys
ZAMAK 3, ZAMAK 5
Available Finish
As machined, Polishing, Sand Blasting, Tumbling, Alodine, Heat treatment, Anodizing, Teflon coating, Electroless nickel, Painting, Powder coating, Electrophoresis
Price
$$$
Lead Time
About 7 business days

Inconel

Inconel is a high-performance nickel-chromium alloy with excellent heat and corrosion resistance, commonly used in aerospace, gas turbines, and chemical processing equipment.
Color
Alloys
Inconel 601, Inconel 625, Inconel 718
Available Finish
As machined, Polishing, Sand Blasting, Tumbling, Alodine, Heat treatment, Anodizing, Teflon coating, Electroless nickel, Painting, Powder coating, Electrophoresis
Price
$$$$
Lead Time
About 7 business days

Invar

Invar is a nickel-iron alloy with extremely low thermal expansion, ideal for precision instruments, clocks, aerospace components, and applications requiring dimensional stability under temperature changes.
Color
Alloys
INVAR 32-5, INVAR 36, INVAR 42
Available Finish
As machined, Polishing, Sand Blasting, Tumbling, Alodine, Heat treatment, Anodizing, Teflon coating, Electroless nickel, Painting, Powder coating, Electrophoresis
Price
$$$$
Lead Time
About 7 business days
ABS
ABS (Acrylonitrile Butadiene Styrene) is a versatile thermoplastic polymer known for its strength, durability, and ease of processing. It is widely used in applications such as automotive parts, consumer electronics, and medical equipment.
Color
Alloys
ABS Beige(Natural), ABS Blac, ABS Black Antistati, ABS Milky Whit, ABS+PC Black, ABS+PC White
Available Finish
As machined, Sand blasting, Tumbling, Teflon coating, Painting, Powder coating, Electrophoresis
Price
$$
Lead Time
About 5 business days
PMMA (Acrylic)
PMMA, also known as acrylic, is a transparent, lightweight plastic with excellent optical clarity, commonly used in lenses, displays, light covers, and signage.
Color
Alloys
PMMA Black, PMMA Transparent, PMMA White
Available Finish
As machined, Sand blasting, Tumbling, Painting
Price
$
Lead Time
About 6 business days

PC

PC (Polycarbonate) is a strong, impact-resistant plastic with high transparency and heat resistance, widely used in eyewear lenses, electronics, automotive parts, and safety equipment.
Color
Alloys
PC Black, PC Transparent, PC White, PC Yellowish White, PC+GF30 Black
Available Finish
As machined, Sand blasting, Tumbling, Painting, Brushed Finish
Price
$$
Lead Time
About 6 business days

POM/Delrin

POM (Polyoxymethylene), also known as acetal or Delrin, is a strong, low-friction plastic ideal for gears, bearings, automotive parts, and precision mechanical components.
Color
Alloys
Dark brown (coffee) POM 100AF, POM Black, POM Blue, POM White
Available Finish
As machined, Sand blasting, Tumbling, Painting
Price
$$
Lead Time
About 6 business days

PC GF30

PCGF30 is polycarbonate reinforced with 30% glass fiber, offering high strength, rigidity, and heat resistance—ideal for automotive, electrical housings, and structural components.
Color
Alloys
Available Finish
Price
$$
Lead Time
About 6 business days

PA(Nylon)

PA (Polyamide or Nylon) is a strong, wear-resistant plastic with good chemical resistance, commonly used in gears, bearings, automotive parts, and industrial machinery components.
Color
Alloys
PA(Nylon) Blue, PA6 (Nylon)+GF15 Black, PA6 (Nylon)+GF30 Black, PA66 (Nylon) Beige(Natural), PA66 (Nylon) Black
Available Finish
As machined, Sand blasting, Tumbling, Teflon coating, Painting, Powder coating
Price
$$
Lead Time
About 6 business days

PC+ABS

PC+ABS is a thermoplastic blend combining strength, impact resistance, and heat resistance, commonly used in automotive interiors, electronic housings, and consumer products.
Color
Alloys
Available Finish
Price
$$
Lead Time
About 6 business days

PA GF30

A glass-fiber reinforced plastic with high strength, excellent dimensional stability and heat resistance, perfect for demanding machining applications.
Color
Alloys
Available Finish
Price
$$
Lead Time
About 6 business days

PP GF30

PP GF30 is polypropylene reinforced with 30% glass fiber, providing excellent heat resistance, low friction, and chemical resistance, commonly used in automotive, industrial, and electrical components.
Color
Alloys
Available Finish
Price
$$
Lead Time
About 6 business days

PP

PP (Polypropylene) is a versatile, lightweight, chemical-resistant plastic commonly used in packaging, automotive parts, textiles, and consumer goods due to its durability and flexibility.
Color
Alloys
Available Finish
Price
$$
Lead Time
About 6 business days

PTFE (Teflon)

PTFE (Polytetrafluoroethylene) is a non-stick, high-temperature resistant plastic with excellent chemical resistance, commonly used in gaskets, seals, bearings, and non-stick cookware.
Color
Alloys
Available Finish
Price
Lead Time

PEI

PEI (Polyetherimide) is a high-performance plastic known for its strength, heat resistance, and electrical properties, commonly used in aerospace, automotive, and medical devices.
Color
Alloys
Available Finish
Price
$$
Lead Time
About 6 business days

PS

PS (Polystyrene) is a rigid, lightweight plastic with good clarity, commonly used in disposable cutlery, food containers, CD cases, and packaging materials.
Color
Alloys
Available Finish
Price
$$
Lead Time
About 6 business days

PPS

PPS (Polyphenylene Sulfide) is a high-performance, heat- and chemical-resistant plastic, ideal for industrial components requiring dimensional stability and durability.
Color
Alloys
Available Finish
Price
$$
Lead Time
About 6 business days

PE

PE (Polyethylene) is a lightweight, flexible, and chemical-resistant plastic widely used in household goods for its durability and versatility.
Color
Alloys
Available Finish
Price
$$
Lead Time
About 6 business days

PPSU

PPSU (Polyphenylsulfone) is a tough, heat- and chemical-resistant plastic, ideal for medical devices, sterilizable components, plumbing fittings, and aerospace parts requiring high performance.
Color
Alloys
Available Finish
Price
$$
Lead Time
About 6 business days

PET

PET (Polyethylene Terephthalate) is a strong, lightweight plastic commonly used in food containers, textiles, and packaging for its durability and recyclability.
Color
Alloys
Available Finish
Price
$$
Lead Time
About 6 business days

PEEK

PEEK (Polyetheretherketone) is a high-performance, heat-resistant plastic with excellent chemical resistance, commonly used in aerospace, medical, and automotive parts.
Color
Alloys
Available Finish
Price
$$
Lead Time
About 6 business days

LDPE

LDPE (Low-Density Polyethylene) is a flexible, lightweight plastic with good chemical resistance, commonly used in containers, toys, and piping applications.
Color
Alloys
Available Finish
Price
$$
Lead Time
About 6 business days

G-10/FR4

G-10/FR4 is a fiberglass-reinforced epoxy laminate, offering excellent electrical insulation and strength, commonly used in circuit boards, electrical components, and structural applications.
Color
Alloys
Available Finish
Price
$$
Lead Time
About 6 business days

HDPE

HDPE (High-Density Polyethylene) is a strong, durable plastic with excellent chemical resistance, commonly used in containers, pipes, toys, and industrial applications for its toughness.
Color
Alloys
Available Finish
Price
$$
Lead Time
About 6 business days

PVC

PVC (Polyvinyl Chloride) is a durable, chemical-resistant plastic used in pipes, flooring, medical devices, and electrical insulation due to its versatility and low cost.
Color
Alloys
Available Finish
Price
$$
Lead Time
About 6 business days

Wood

Wood is a natural material from trees. High-density woods are machinable. It’s a common material for consumer products such as furniture and artwork.
Color
Alloys
Birch, Oak, Beech, Mahogany, Pine, etc.;
Available Finish
Price
$$
Lead Time
About 6 business days

Glass

Glass is a hard, transparent material made from silica, used in windows, containers, lenses, and decorative items due to its clarity, strength, and versatility.
Color
Alloys
low-iron glass, tempered glass, etc.;
Available Finish
Price
$$
Lead Time
About 6 business days

Stone

Stone is a durable, natural material used in construction, landscaping, artworks (e.g., statues, jewelry), and inspection machines, valued for its strength, beauty, and versatility.
Color
Alloys
Granite, Marble, Artificial Stone, Quartzite, Sandstone, etc.;
Available Finish
Price
$$
Lead Time
About 6 business days

Ceramics

Ceramics is a super-rigid, insulating high high-temperature resistant material. It is widely used in electronic products. It can be used as a cutter as well.caping, artworks (e.g., statues, jewelry), and inspection machines, valued for its strength, beauty, and versatility.
Color
Alloys
Alumina, Zirconia, Magnesium oxide ceramics etc.;
Available Finish
Price
$$
Lead Time
About 6 business days

CNC Machining Finishes

Surface finishes are essential for enhancing the appearance, durability, and functionality of precision-machined parts. As the final step in the CNC process, surface finishing improves wear resistance, corrosion protection, sealing, and friction performance through mechanical, chemical, or thermal treatments. Explore our list of popular CNC surface finish options to meet your specific functional and aesthetic requirements.

As machined

This finish leaves the surface directly from the CNC machine, providing a cost-effective option with visible tool marks.

Sanding & Polishing

This process smooths the surface by removing tool marks, resulting in a refined finish with varying levels of gloss and texture.

Sand, Bead Blasted

This process creates a uniform, matte texture by propelling fine abrasive particles onto the surface, removing imperfections and tool marks.

Painted

A protective and aesthetic coating is applied to the surface, offering a smooth, uniform finish with customizable colors and textures.

Powder coat

A durable, wear-resistant finish applied electrostatically and cured under heat, providing a uniform, protective coating in various colors.

Anodized

An electrochemical process that enhances surface durability, corrosion resistance, and appearance, available in various colors with a smooth or matte finish.

E-Coating

An electrostatically applied coating that provides a uniform, corrosion-resistant finish with excellent adhesion, commonly used for protective and aesthetic purposes.

Nickel Plating

A protective and decorative coating that enhances corrosion resistance, wear resistance, and surface hardness while providing a smooth, metallic finish.
Process
Tolerance (Inches)
Tolerance(Millimeters)
3-axis CNC Milling
±0.005″
±0.13 mm
5-axis CNC Milling
±0.005″
±0.13 mm
Router
±0.005″
±0.13 mm
Router (Gasket Cutting Tools)
±0.030″
±0.762 mm
Engraving
±0.005″
±0.13 mm
Rail Cutting
±0.030″
±0.762 mm
Screw Machining
±0.005″
±0.13 mm
Steel Rule Die Cutting
±0.015″
±0.381 mm
Surface Finish
Typical finish for CNC machined parts is 125 RA, depending on material and process.
Note:
Tolerances listed are standard references. Actual achievable tolerances may vary based on part size, geometry, material, and machining complexity.
Contact
Contact our team if you need further information

CNC Machining Design Guidelines

Read our practical guide to optimize production efficiency. 3ERP experts offer immediate feedback to ensure optimal results in CNC machining, helping you consistently achieve precision tolerances. Following these best practices not only enhances precision and shortens lead time but also helps control your CNC machining service cost by reducing unnecessary complexity and rework.

Part size

Machined parts are limited in size by the machine envelope. 3-axis mills typically have a larger build size than multi-axis machines.

Feature alignment

For 3-axis machining, it costs more to add features to multiple faces. It can therefore help to design parts with holes and and other features aligned on a single face.

Fillets

Internal fillets should be as large as possible to allow a large-diameter tool to be used. The radius of the internal fillet should be greater than 1/3 the cavity depth to prevent tool damage.

Wall thickness

Metal parts typically require a minimum wall thickness of 0.8 mm, while plastic parts require 1.5 mm. Thinner walls are vulnerable to vibration and deformation.

Cavity depth

To minimize chatter, tool deflection, and other issues, the depth of machined cavities should be no more than 4x the width.

Holes and threads

Hole and thread diameters should correspond to standard drill bits and threading tools. Hole depth should generally be no more than 10x the diameter.

Undercuts

T-slot undercuts can be around 3–40 mm wide. Dovetail undercuts work best at a standard angle of 45 or 60 degrees.

Design Tips for CNC Milled Parts

CNC Machining for Various Industrial Applications

Our CNC machining services have been qualified by worldwide customers from diverse industries. We specialize in delivering high performance CNC machined parts for a wide range of applications, serving industries such as those listed below, and beyond.

CNC Machining FAQ

CNC (Computer Numerical Control) machining is a precise and efficient manufacturing process that uses automated cutting tools to shape metal or plastic parts. Depending on part complexity, we use 3-axis, 4-axis, or 5-axis milling machines, lathes, or routers.

Once we receive your 3D CAD model, our skilled machinists program optimized tool paths to reduce costs and ensure tight tolerances. Learn more about the CNC machining process.

CNC machining offers key advantages over 3D printing, injection molding, and laser cutting:

It’s fast and cost-effective for simple parts, like base plates with holes or grooves. CNC machines achieve tight tolerances of ±0.01 mm and deliver smooth surface finishes down to Ra 0.8—ideal for painting or anodizing. They also handle a wide range of part sizes, from large components up to 6 m x 30 m to tiny features cut with 0.05 mm tools on precision 5-axis mills.

CNC machining is more cost-effective for simple parts. Complex geometries are possible but often require multi-axis setups, increasing time and cost. Tool access limits design flexibility, as cutting tool size and angle affect reach. High startup costs can raise per-part pricing for small batches. As a subtractive process, CNC also generates material waste. However, raw material blanks are typically cheaper than the powders used in additive manufacturing, helping offset waste-related costs.

Yes. As soon as we receive your RFQ, our engineers will review the CAD files and offer the design feedback and optimization suggestion for CNC machining if needed. In order to get better CNC machined parts quality and sort out the points to lower the CNC machining cost which affect the unit price.

3ERP owns two CNC machining shops with over 60 sets of CNC milling and CNC turning machines. And we have more than 40 experienced technical experts, therefore we can guarantee to manufacture 5000 pcs different types of CNC machined parts in-house. Besides that, thanks to our verified manufacturing partners from our manufacturing network, we can offer extra CNC machined parts unlimitedly.

3ERP is known as one of the best CNC machining companies in China in terms of quality, speed, and customer service. With high-quality CNC machines, we can easily achieve high-precision tolerances and standards of +/- 0.02mm and can even get within +/- 0.01mm. But keep in mind that it can have an impact on the cost.

Our production engineers review every RFQ we get from customers to make sure the material and CNC machining cost are calculated properly. The online CNC machining quotation system from most of the manufacturing platforms is not yet accurate enough. Read more about the case study.

First of all, make sure the parts are designed friendly for CNC machining process. For example, avoid the features like sharp corners, deep pocket and thin walk. Secondly, select the right CNC machining companies for your projects. For the simple, small parts, you can easily find the small CNC machine shops to make parts at a better price. If you need precision parts with complex geometries, then a CNC machining company like 3ERP who have precision multi-axis CNC mills and lathes and inspection facilities fits better.

Referring to our previous CNC machining orders, over 90% of them are finished in around 7 days. Simple CNC machined parts can be done within 2 days, while it might take 15+ days to make complex or big CNC machined parts. Quantity is another matter to be considered. From our CNC machining manufacturing networks, we can also machine your parts from our CNC machining shops which is close to your location in the US and Europe which shorter the shipping time.

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