Why Use 3ERP for
Custom CNC Machining Services?

3ERP provides a custom CNC machining service to engineers, product developers, designers and more. We offer rapid prototyping, small-batch machining and high-volume production. Here are the reasons why you should select 3ERP as a manufacturing partner. With in-house advance equipment which includes HAAS CNC mills and lathes, Hexagon CMMs and Olympus XRF analyzer. We can guarantee your CNC parts are made in correct material and dimension. Our experienced engineers have built up rich, deep experience from many previous CNC machining projects in various industries. They can handle any type of tight tolerance CNC machined parts with complex geometries. We offer consistent high-quality CNC parts that are full inspected by our quality control department when they are ready to ship out to ensure parts are built to specification and free of defects. We have enough capacity to offer fast turnaround CNC machining services, by using in-house facilities and our qualified manufacturing network.
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What is CNC Machining?

CNC, or computer numerical control machining, is a widely used manufacturing process that uses automated, high-speed cutting tools to remove material from a metal or plastic workpiece until the desired geometry is achieved. Standard CNC machines include 3-axis, 4-axis, and 5-axis milling machines, lathes, and routers. Machines may vary in how CNC parts are cut—the workpiece may remain in place while the tool moves, the tool may remain in place while the workpiece is rotated and moved, or both the cutting tool and workpiece may move together

When a machinists receive the CAD (computer-aided design) model which is also called 3D file, they will start from programing tool paths based on the 3D file. A skilled machinist knows how to optimize the tool paths to lower CNC machining cost as well as to achieve tight tolerance. CNC machines can cut almost any material such as metal alloys, plastics, wood, stones, ceramics and more. Making custom machined parts needed for nearly every industry, including automotive, robotics, medical, aerospace, electronics and industrial. 3ERP provides CNC machining services and offers custom CNC quotes on various of materials ranging from commodity aluminum, steel, stainless steel, ABS, acetal to advanced titanium, Inconel, and engineered plastics like Teflon, PPS, PEI and PEEK. Learn more about CNC machining process

CNC Machining machine operating
CNC Machining on Steel

Our CNC Machining

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.
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CNC Milling Service

With 32 sets of 5-axis CNC milling machines in-house which allows us to mill tight tolerance plastic and metal parts with complex geometries easily. And we also offer low-cost machined parts by using our 3-, 4-axis milling machines.

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CNC Turning Service

CNC turning is a more efficient method to manufacture round components from plastic and metal bars or tubes, such as worm shafts. When combined with live tooling, milled geometries can be achieved simultaneously.

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EDM & Wire-Cut Service

EDM and wire-cut is one of the CNC machining processes which uses copper, graphite pattern or molybdenum wire to achieve the design for sharp corners, undercuts and remove whatever un-needed material from workpieces. EDM is also widely used for rapid tooling and production mold making.

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CNC Grinding Service

If you need a super flat surface part, or round part that needs OD and ID +/- 0.005mm in tolerances, our CNC grinding machining service will be the best match of your production needs for such type of parts.

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Swiss Machining Service

Swiss machining is an efficient way to produce complex, or slender component. By moving both live tooling and the workpiece, we can always cut the material which is close to the workpiece holder. To avoid deformation compared to traditional CNC lathe.

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CNC Routing Service

Besides standard milling service for parts in engineering plastics or metals, we also offer CNC routing service for prototypes and parts in soft materials such as EPS foam, EVA, woods.


CNC Machining Tolerances, Materials & Surface Finishes


Tolerances and Standards

With a wide range of CNC mills and lathes, we are able to provide standard tolerance CNC machined parts with the most economical price and CNC machining precision parts for high-end products. When working with 3ERP, we guarantee all parts will be made according to your specification. If 2D drawings are not available, you can also indicate with ISO 2768.


Machinable Materials

Wide range type of industrial-grade CNC machining materials such as ABS, POM, PEEK, stainless steel, brass, copper and more can be used for custom parts, giving you lots of material selection options to complete prototypes and production runs of custom parts. Learn more about our plastic machining and metal machining.


Surface Finishes

3ERP offers wide variety high level surface finishes such as bead blasted, anodized (type ii, type iii), chromed, powder coating, zinc plating, nickel plating. We only list some of the common surface finishing options. There are more surface finish options for CNC machined parts.

CNC Machining Design Guidelines

Part size
Machined parts are limited in size by the machine envelope. 3-axis machines 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.
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.
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 Learn More

From Concept to Production

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

Prototype Machining

From 3ERP, you can get your CNC machined prototypes done in days, super shot lead times allows you to verify the design fast.

  • Instant quotes
  • Instant DFM feedback
  • Excellent quality
  • Short lead time
Low Volume

Low-Volume Machining

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

Production Machining

Using CNC machines and robots is a best option for big volume production machining which allows us to avoid heavy labor. Decrease the cost significantly.

  • Experienced engineers for DFM optimization
  • A professional project manager working in your time zone
  • First Article Inspection
  • Guaranteed consistent quality
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into production today
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CNC Machining

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 +/- 0.02mm of tolerance 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 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.

Advantages and Challenges of CNC Machining

Here we present some of the main advantages of CNC machining compared to other manufacturing processes such as 3D printing, injection molding, urethane casting, laser cutting, plasma cutting, or other sheet metal fabrication processes. Cost-efficient: The CNC machining process is a high-speed manufacturing process for certain types of parts. CNC machines with a powerful spindle and good machine tools allow us to remove raw material fast. If the part geometry is simple (for example, a solid base plate which needs holes, threads, steps, or grooves) very small amounts of raw material are removed. In this case, the unit price for CNC machining will be much lower than 3D printing, because it would take many hours to print such a part. More precise: On a good CNC mill or lathe, the machine tolerance is +/-0.005 mm, and if we can remove 0.005 mm in the final cut from the workpiece, that means we can easily get parts machined with a +/-0.01 mm tolerance. Compare this to the 3D printing process, in which parts are printed layer by layer. The minimum layer height is 0.05 mm, which means the parts tolerance can’t be less than 0.05 mm. Better for surface finishing: Post-processing is always needed for cosmetic parts, so it is very important to achieve a good surface finish at the first stage. When the RPM of the CNC mill goes up to 15,000 and the CNC lathe up to 6,000, the CNC machined part surface roughness is less than Ra 0.8, which is good for bead blasted, painted, or anodized surfaces without sanding manually. Meanwhile for parts made from SLS, SLM, or DMLS processes, the surface roughness is far more than Ra 3.2. More flexible part sizes: A large CNC machine center can have a table measuring 6 m x 30 m or larger, which means that very big parts can be milled. And as far as we know, the biggest lathe was built with a maximum 5 m diameter. At the other end of the scale, with precise 5-axis CNC Mills and R0.05 mm cutting tools, we can mill a tiny geometry from a 1 mm x 1 mm x 1 mm

Simple parts are more economical than complex ones during CNC machining. While geometric complexity is possible, it requires steps that increase the cost of the operation, such as multi-axis machining or multiple setups. Design complexity is limited by tool access: the angle and size of the cutting tool determines which areas of the workpiece it can and cannot reach. Startup costs can also be high for CNC machining. Although it is a tool-free process, giving it lower startup costs than molding and casting, machining requires a slow setup and tool loading procedure that only an experienced machinist can perform. This adds significant cost per part if only one or a handful of parts are machined per setup. Another challenge for CNC machining is material waste. Because machining is a subtractive process, a considerable amount of the workpiece is turned into chips (swarf) that are discarded after machining. However, blanks (pieces of raw material for machining) cost much less than some other forms of material — additive manufacturing powders, for example.

cnc machining advantages and challanges

CNC Machining for Various Industrial Applications

Our CNC machining service have been qualified by worldwide customers from different industries. We have been offering CNC machined parts for various industries which include the below list and more.