Custom CNC Machining

Table of Contents

Custom CNC Machining

Custom CNC machining is a process in which metal or plastic parts are manufactured with the help of computer numerical control machine such as cnc mill and cnc lathe. This type of machining is used in industries like aerospace, automotive, and electronics. The main advantage of this process is that it can produce parts which are complex shapes with precise dimensions.

When looking for a reliable, quick-turn supplier of machined plastic and metal components? Now you are in right place to start, with our advanced CNC machines, our unmatched in-house capacity ensures your parts are shipped on-time, every single time. At 3Q MACHINING, our ISO9001-certified CNC machining facilities are designed for both rapid prototyping and volume production of end-use components.

CNC machining technology is a subtractive manufacturing process that automates the machine tools with help of Computer Aided Design (CAD) and Computer Aided Machining(CAM) to carry out various operations for cutting/drilling metal or plastic workpiece from solid block final desired shape.

CNC machining technology has been around for decades. It was originally used for cutting metal shapes from solid blocks of steel, aluminum and brass. Now the process is getting more precision and more popular to replace the old-school manual machines in different the manufacturing industrials.

Prototype CNC machining is a manufacturing process that makes it possible to produce 1 pcs or small batch prototype sample or models for new products  with complex geometry and high accuracy.

The process of prototyping is an important step in the design and manufacture of a product. It allows the designer to test their design and make adjustments before going into production. The part can be manufactured from either metal or plastic, and it can be as large as desired, depending on the machine that is being used.


Nowadays, 3D printing is getting more and more popular to replace prototype cnc machining due to higher efficiency, high precision, but lower cost, especially when only need 1 pcs or couples of prototype samples. The prototype cnc machining only suitable for small batch prototype projects or high quality surface finishing parts, because 3D printing is higher cost with small batch (30~100pcs), and can’t have good machined surface as cnc machining.

In the future, we can see more and more projects will combine with CNC Machining technology and 3D printing for high precision parts with low cost.

How much does custom CNC machining work cost?

If you only want to make 1pcs or couples of rapid prototype samples for your projects, it could be as low as $100 in total to start. The cost of custom cnc machining work could be variety that depends on the complexity of design, raw material cost, what type of machine will be used, how much time will be used per product unit, the order quantity, and the surface treatment.

  1. Quantity
  2. Machines
  3. Raw Material
  4. Machining Time
  5. Surface Treatment
Sometimes you also need to considering the lead time if the parts are urgent need, that you probably choose a cnc machining shop nearby although it might has much higher cost, so understanding of your budget and product requirements is priority before start source a trusted supplier, get more answer and details you can read the article “how much does cnc machining cost

Our On-demand CNC Machining Services - help you to manufacture what you want

We offer one stop solution for your custom parts from CAD drawing to final shipment, no MOQ to start from 1pcs prototype sample and low cost for mass production.

1. Upload a CAD to start (STEP, STP, IGES, IGS, SLDPRT, 3DM, SAT, STL, OBJ or X_T).

2. Our instant quotes are based on the actual material price & part price, and include shipping and customs up front.

custom cnc machining quote

Main CNC Machining Processes:

CNC Milling

CNC milling is a subtractive manufacturing process that uses 3-axis milling, 4-axis milling, 5-axis milling machines to cut/drill solid plastic and metal blocks into final parts, more axis is suitable for more complex parts especially.

CNC Turning

CNC Turning/Lathe is different to CNC milling, in which the cutting tool rotates and is directed from multiple angles at the workpiece, which is usually stationary. It is generally used to create round or tubular shape parts precisely.

Main CNC Machining Materials:

There are wide selection of materials can be made with CNC Machining techniques, rapid prototype or big volume production, and the most popular materials are metal and plastic for the cnc machined parts.

Metal materials:

  1. aluminum alloy
  2. steel
  3. stainless steel
  4. brass / copper
  5. titanium

Plastic materials:

  1. PTFE
  2. NYLON
  3. PEEK

PEEK for aerospace industry

CNC Machining Surface Finishing:

We offers a high quality surface finishing service for all components and parts regardless of the machining method used in producing them. We have some skilled experts who only handle finishing assignments so the quality of work done on your products is of exceptional quality. If you desire a perfect finish for your prototypes and other manufactured components get in touch with our customer services team for a quick and accurate quotation.

This is standard finish for hard plastic or metal machined parts which don’t have color or high quality roughness or protection requirements. Parts are machined and deburred, sharp edges are chamfered.


Smooth machining is better quality than ‘As machined’ finishing which is with slightly less evident machine marks. Parts are machined at a lower feed, no polishing is applied

Finer-looking machining obtained either through higher-precision machines, lower feeds, sharper tools, or a combination of all the above. Machining marks are less evident.

Parts are manually polished in multiple directions. Surface is smooth and slightly reflective.

Parts are brushed manually with #400 – 600 grit sandpaper in order to reduce machining marks. Ideal to slightly reduce the roughness of the finish.

Parts are bead blasted with glass beads which results in a grainy texture and reduced machining marks, it has smooth and rough bead blasting.

Powder coating is a strong, wear-resistant finish that is similar with painting but more durable, it is popular for metal parts in outdoor/kitchen market.

Applicable on steels, black oxide is a conversion coating used to improve corrosion resistance and minimize light reflection.

PVD (physical vapor deposition) coating, also known as thin-film coating, is a process in which a solid material is vaporized in a vacuum and deposited onto the surface of a part. These coatings are not simply metal layers though.

Parts are machined to Ra1.6µm and electroless nickel plated. Ideal for wear abrasion and corrosion resistance, not for cosmetic purposes.

Parts are bead blasted, anodized type II and bright dipped. Results in glossy color. Ideal for cosmetic parts needing an increase in corrosion resistance.

Parts are anodized (type II) directly after machining. The most cost-effective anodizing option; ideal for non-cosmetic, functional parts. Used to improve wear and corrosion resistance.

Parts are manually brushed with fine sandpaper to attenuate the machining marks and then anodized. Ideal for increasing the corrosion resistance of the part. Typically results in a glossy aspect.

It is known as chem film or chemfilm, Alodine® is a chromate conversion coating that protects aluminum and other metals from corrosion. Related products include Iridite®, TCP-HF, and Bonderite®. The process of applying a chromate conversion coating is referred to as chromating.

Parts are bead blasted and anodized type II. Ideal for increasing the corrosion resistance of the part. Results in naturally matte colors. For glossy colors, please select the bead blasted + glossy anodizing option.

Parts are machined and an anodizing type III coating is directly applied to the surface. Ideal to improve corrosion and wear resistance of components.

Parts are brushed and electropolished. Ideal to reduce the micro-roughness of the part.

Parts are machined and a chromate conversion coating is applied. Ideal to increase the corrosion resistance of the part while maintaining its conductive properties. RoHS compliant.

Questions and Answers

The frequently asked questions and the most important things you should know for custom cnc machining services.

CNC machining is a fast, accurate and versatile solution for making end-use plastic and metal parts in any quantity, it could start with 1 pcs, without the need for investing in hard tooling or expensive set-ups. No matter how simple or complex the parts you want to make, cnc machining technqiue can make the final parts as your design drawings.

CNC machining starts with a computer, on which designers prepare a part using CAD (Computer-aided Design) software. This digital part is then converted into a format that can be recognized by a CNC machine.

Instructions are sent to the CNC machine in the form of  “G-Code” after which the machine can start cutting.

Most CNC machines have a “worktable” and work holding device to keep a block of material — known as the “workpiece” — in place. The worktable may or may not move, depending on the style of the machine.

When machining starts, the cutting tool makes contact with the workpiece, cutting away layers of material. The tool and/or workpiece is moved and/or rapidly rotated according to the G-Code instructions so that cuts are made in exactly the right places until the part is finished.

Color: Pantone Number

Logo: AI


Sample lead time: 7days

Tooling lead time: 35 days

Production lead time: 7~30days

Usually we book the shipment with your appointed forwarder, or can ship to your warehouse with our shipment company

We also working with DHL/FEDEX/UPS for  long term relationship to have competitive express shipment with fast delivery.

CNC machines include CNC mills, CNC turning machines (or lathes), CNC routers, and Electrical Discharge Machining (EDM) machines.

CNC mills have rotating cutting tools that are moved to different areas of the workpiece to make cuts and can be used to make many different pats. CNC lathes work the other way, rotating the workpiece against a stationary cutting tool, and are used to make cylindrical parts.

CNC routers are similar to CNC mills, but have less power and cannot cut the hardest materials. They can, however, be faster than CNC mills.

EDM uses electrical discharges (sparks) instead of a sharp cutting tool to cut material. No physical contact is made between the tool and the workpiece.

CNC machines are often defined by their number of axes. More axes mean they can move their tool and/or workpiece in a greater number of ways, giving greater cutting flexibility and the ability to make more complex parts in a shorter time.

3Q Machining 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.

MOQ: From 1 piece to ~3000pcs each color each part

Sample payment: 100%

Tooling payment:50% deposit, 50% balance after sample approval

Product order payment: T/T 30% deposit, 70% after pre-shipment inspection

It’s no problem to arrange third party inspection before shipment, please book the inspection date 7 days in advance

Author: Mose Li

Author: Mose Li

Director of Project Engineering at 3Q Machining

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