The Ultimate CNC Machining Guide of Machining Shop

CNC machining guide

What Is CNC Machining?

CNC machining technology is controlled by the instructions issued by the computer numerical control programs.

The computer program directs the cutting tools to move in specific ways to manufacture the end product by removing material from the workpieces.

Since machinists can’t communicate with CNC machine tools. Hence, we need a program or software to resolve this problem. 

Computer-Aided Design (CAD) is used at a machine shop to deliver instructions to equipment. 

CAD Programming

CAD software creates 2D and 3D models for the parts nee to be machined.

The machine tools work in such a manner that they produce the end product following the model design.

The work of CNC machining is based on the following stages.

Creation Of CAD Models

The CNC machining starts with creating computer-aided design models.

As a result, 2-dimensional and 3-dimensional models of end products are produced firstly.

Conversion Of CAD Models To CAD Files

The CAD model can be converted into an understandable CAD file.

This file is called G-code, and converting the computer-aided design into CAD files requires software, this software is named CAM.

You can also convert it using other tools, but they offer fewer features than CAM software.

Configuration Of CNC Machine

CNC machine tools are configured during this stage. It includes the correct positioning of the workpiece and machine settings etc.

Execution Of Machining Operations

After the completion of the configuration stage, the machining operation is started. 

The programs once be started, the machine keeps on working until the program ends.

Types Of CNC Machining Operations

CNC Turning

CNC turning is a manufacturing process recognized by removing material from a rotating workpiece through a stationary cutting tools with a single point.

It is opposite to the milling operation in which the cutting tool rotates instead of the workpiece.

Turning operations are mostly done for the production of cylindrical and round parts such as shafts or rollers, etc.

CNC turning

CNC Milling

CNC milling is a manufacturing method that involves material removal from a workpiece through the rotation of multi-point cutting tools.

The process mainly includes tapping, boring, chamfer milling, end milling, and face milling.

It manufactures a wide range of products with complex geometry.

mill turn machining

CNC Drilling

CNC drilling is a manufacturing process employed to create cylindrical holes in the desired workpiece by using multi-point drill bits.

The drill bits run at the right angle or perpendicular to remove material from the workpiece. 

CNC drilling

Pros & Cons Of CNC Machining

Here below are the advantages and disadvantages of CNC machining.

Pros Of CNC Machining

1. Continuous Operation

CNC machines can offer non-stop working, where multiple pre-set operations can be performed continuously under program control.

2. Advanced Technology

Advanced CNC software technology allows the creation of designs that are impossible to complete manually.

3. High Precision And Accuracy

The entire machining process is controlled by computer software. Therefore it produces highly accurate and precise parts.

4. Time-Saving

CNC machining is a time-saving process. The parts produced using this method can usually be produced by as few set ups as possible with minimal errors and without excessive operations.

5. No Degree Demand

The operators working at machine shops can be fine without a degree.

Mastering the machining technology can be performed without any specific degree. They just need to be trained to operate it.

Pros-Cons for CNC machining

Cons Of CNC Machining

1. High Cost

The cost of CNC machining is much higher than traditional manual machining operations due to the expensive machines and tools. Therefore, it can disturb your budget.

2. Unemployment

CNC machining operation requires less number of workers. Thus less need for workers will cause unemployment.

3. Loss Of Skills

The process of CNC machining demands no special skills. It causes the loss of the skills used in manual operations. This can result in skills deficiency in the current generation.

What Materials Can Be Machined?

There are no limitations on the machine shop’s CNC machining material. You can have a wide range of materials having varying properties to machine. 

Here are the most commonly used materials available at machine shops.


Metals are recommended materials because they produce parts with greater precision.

metal material


    • Carbon steel
    • Alloy steel
    • Mild steel
    • Tool steel


      • Brass C260
      • Brass C360


        • Aluminum 2014
        • Aluminum 2024
        • Aluminum 5052
        • Aluminum 5083
        • Aluminum 6061
        • Aluminum 6063
        • Aluminum 7050
        • Aluminum 7075
        • Aluminum MIC6


          • Titanium Grade 1
          • Titanium Grade 2
          • Titanium Grade 5


            • Copper C101
            • Copper C110

            Stainless Steel

            Stainless steel is a good choice for CNC machining.

            In order to choose a specific stainless steel grade for machining, you must follow the following considerations.

              • Grade availability
              • Magnetism
              • Strength
              • Price
              • Heat treatment


              Plastics are prioritized for CNC machining because of their excellent physical properties and greater strength. 

              plastic material

              Some of the main plastics used for machining are mentioned below.

                • Nylon
                • High-Density Polyethylene
                • Polypropylene
                • Polycarbonate
                • Teflon
                • Acrylic
                • ABS
                • PEEK
                • PET
                • POM

                Surface Finishes For Machined Parts

                The surface finishes are applied to the parts to increase the aesthetic appearance. 

                surface finish parts

                Moreover, it also enhances the uniformity and corrosion-resistant properties. Here are some common surface finishes for the machined parts.


                Anodizing is a common surface finishing process, especially for aluminum parts.

                Anodized aluminum parts not only have good corrosion resistance but also can achieve beautiful colors.

                Electroless Nickel Plating

                In electroless nickel plating, a layer of the nickel-phosphorus alloy will be deposited on the surface of the part, such as steel or aluminum. 


                As an electrochemical process to improve the surface finish of parts, electrolytic polishing is particularly useful for polishing irregular parts with hard-to-reach surfaces.

                It reduces the roughness resulting in providing a shiny surface.

                Bead Blasting

                It is a multi-purpose, flexible technique in which highly pressurized steel or glass beads shoot at the parts. 

                It is usually done in a closed chamber. It helps in improving surface appearance along with providing a non-reflective surface.

                Powder Coating

                Powder coating involves coating a dry powder on the surface of the parts. 

                It is electrostatically applied on the substrate. It is done to provide a hard finish to the material surface.

                Common Defects For CNC Machining

                Learn more about the common defects of CNC machining that have a positive effect on optimizing design and avoiding machining risks.

                quality assurance

                Material Burning

                The low feed speed and blunt tool may cause material burning during machining. 

                The material may also burn if you put the tool in an incorrect spindle and use the wrong speed of the spindle.

                Misalignment Of Tool

                Tool misalignment is also one of the machining defects.

                At machine shops, this defect mostly results in the inaccurate dimensions of the parts machined.

                Chatter Error

                During machining, the workpiece and machine may show uncontrolled vibrations. 

                It usually happens due to poor configuration of the machine.

                Improper Clamping

                It is caused due to a damaged tool insert and holder or a bad surface finish. 

                Uncontrolled vibrations between the cutting tool and the workpiece can cause improper clamping.

                Poor Surface Finish

                Poor surface finish during machining is caused due to bad cutting actions, low cutting speed, and greater feed rate.

                Why Sindparts?

                As a modern machine shop, we specialize in offering high-quality CNC machining services for various industries.

                Our machinists use the latest precision CNC machining technology e.g. 3 or 5-axis CNC to ensure that all parts meet the highest standards of quality and accuracy.

                We have extensive experience providing customized component parts for applications in the aerospace, automotive, medical, electronic, and telecommunications industries.

                We are dedicated to providing superior service and fast turnaround time for our valued customers, so you can rely on us to get the job done quickly and efficiently.

                Unlike other machining companies, we practice working with you, not just for you. Quality and service are always put first.

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                China On-demand CNC Machining Services Supplier, With Diversified Customized Finishes and Materials. 

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