CNC VS Manual Machining, Which One Is Suitable For You?

CNC machining has become the core pillar of modern manufacturing technology. Most industries rely on this technology to handle the needs of multiple production stages. From prototype production to batch production, CNC processing can be done. CNC machining or computer numerical control has become a faster and more efficient manufacturing strategy.

The manual processing shall be operated manually by experienced or well-trained machinists. Through the final comparison between CNC machining and manual machining, the advantages of CNC machining seem limitless.

However, some manufacturers rely on manual processing tools to produce prototype parts. In particular, manual processing plays a prominent role in the industry and in small batch rapid prototyping.

This article will give a side-by-side overview of these two technologies and understand their performance on each important parameter.

CNC And Manual Machining Principle

CNC Machining Principle

CNC machining is a manufacturing process in which the cutting tool is controlled by an automatic system to remove material from the workpiece. This is an extensible process that can complete all work from prototype production to mass production.

Automatic CNC machining requires digital files with cutting and machining instructions. Therefore, the CNC machine process needs various tools to manufacture machined parts, and engineers and machinists build a digital tool library to interact with the CNC machine.

These machines can be operated automatically by applying digital instructions and design startup in CAD software (computer-aided design). The 3D model created by the software determines the attributes and dimensions required for the final part.

Because the CAD-CAM software package is bundled with some of the software programs, the production can continue in the same program. If CAD and CAM software manufacture the same product family, no document translation is required. Otherwise, you need to import the CAD file.

CNC machining

Manual Machining Principle

The tool in this process can be simple or complex, but the relative motion is completed by the operator.

Manual machines are controlled by hand, including any traditional machines, such as band saws, drilling machines, grinders, end mills and lathes. Using these manual machines, mechanics can create a large number of prototype projects for various purposes. However, compared with CNC processing controlled by automation or computer, manual processing requires more time and more attention to perform any function.

CNC Machining vs Manual Machining- Advantages and Disadvantages

There is a big difference between CNC machining parts and manual machining parts. These differences can usually be found in the visual inspection of finished parts or by comparing their production quantities. The following describes their respective advantages and disadvantages, and can consider which is more suitable according to the actual situation.

Advantages Of CNC Machining

Improve product quality

CNC machining basically eliminates the possibility of human error in the machining process. The technician compiles the product specification into the special software program connected to the CNC machining equipment. The software program then controls the movement of each tool to ensure accurate milling.

CNC lathe can repeat exactly the same movement thousands of times without deviating from the programming specification. This consistency can eliminate any defects that may occur in the production and processing stage, thus improving the overall quality of the processed products.

Improve manufacturing efficiency

Efficiency is what all manufacturing facilities try to maximize. The higher the efficiency of the manufacturing process, the higher the profit of the product. CNC machining can improve the overall efficiency of the milling process.

Because the machining process is automated by CNC lathe, the work can be completed at a faster speed. Computer-controlled tools can execute faster than manually controlled tools. This allows you to increase productivity and maximize the overall efficiency of the mechanical workshop.

Less manpower and low maintenance requirements

CNC machines do not require a large number of experienced operators in the manufacturing process. That is to say, only a skilled mechanic can perform production tasks. Although CNC machines operate all day long, they only require little maintenance compared with manual machines. They only need occasional maintenance.

Maximize employee safety

The mechanical workshop itself is a dangerous workplace. In any manufacturing environment, employee safety is always an issue. Using CNC processing instead of manual processing is a good way to improve the overall safety of workers.

During CNC machining, employees do not need to contact any machining tools directly.

Once the product specifications are programmed into the software of the CNC machine, employees can stand behind the protective device or transparent door and keep a safe distance from the actual processing process. This can prevent the possibility of serious injury caused by flying debris or tool breakage during processing.

Disadvantages of CNC machining

Although CNC machining is the best choice in manufacturing, there are some disadvantages in this process. These disadvantages are:

Due to the high price of machines, CNC equipment requires a high initial investment. Installation cost is another major factor to be considered.

There is an additional stage of computer programming that requires skilled programmers to create code for components.

The quality of machine operation depends on the skill of the operator. Therefore, skilled mechanics are required to obtain good results.

Although there are few failures, in case of failure, the manufacturer needs to call skilled professionals.

The unemployment rate has increased due to the higher degree of automation and the reduction of labor demand.

After the part programming is completed, it is necessary to conduct debugging and error detection to prevent the NC machine tool from crashing during operation. The debugging part requires extra time and skills.

Advantages Of Manual Machining

Although CNC machining has cutting-edge facilities for producing precision machined parts, it also has its value in manual machining. The following are the advantages of manual processing.

Manual machining can also be used to produce plastic and metal parts and achieve the same purpose.

Manual machines require more tools and more time to complete the manufacturing process. Therefore, you can use this process for small operations and parts manufacturing.

For simple metal shapes, the traditional/manual processing method is recommended because it is cheaper.

Parts can be machined without programming. Machinists can work directly on parts.

For small projects or one-time orders, the turnaround time will be shortened because the machinist does not have to go through the programming stage.

Manual machining can handle customization well, because small changes in the project do not need to start from scratch.

Mechanists do not need to be skilled in operating computerized panels.

In case of failure, machines such as manual milling machines are easy to repair, and the maintenance cost is very low.

Disadvantages Of Manual Machining

Manual machining may have several disadvantages for manufacturers, such as:

The manufacturing speed of this process is quite slow. CNC processing can be completed in a few minutes, which may require several hours of manual processing.

It cannot handle modern mass production requirements and quantities.

The precision of manual processing is quite accurate and contains human error.

Due to the lack of accuracy and higher error probability, the number of rejection is more. This leads to more waste and increased costs.


The decision whether to use CNC machining or manual machining mainly depends on your requirements and production objectives. I hope that the above introduction can better help distinguish and select appropriate processing methods.

If the high initial cost of the CNC machine prevents you from using this technology, the CNC machining of SANS may be a good solution. You can choose a variety of options, for example, we have both manual milling machines and multi-axis CNC machines, CNC milling machines, CNC lathes and many other manufacturing options, providing you with high-quality and high-precision components minus the same additional costs.

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