What is CNC Machining Magnesium and Safety tips?

CNC machining parts

In the vast realm of manufacturing, various materials have their unique characteristics that make them ideally suited for certain applications. One such material that holds significant prominence in many industries is magnesium.

But why is this particular element so sought-after, and how does it relate to the critical process of CNC machining? Let’s delve into these topics and more in our exploration of CNC Machining Magnesium.

CNC machining parts

What is CNC Machining?

CNC or Computer Numerical Control machining is a process used in the manufacturing sector that involves the use of computers to control machine tools. This technique provides enhanced precision, efficiency, repeatability, and complexity while minimizing human error.

There are various methods of CNC machining, each with their own benefits depending on the application. For instance, CNC milling is perfect for producing custom parts with high precision. It involves a rotating cylindrical tool moving along multiple axes to cut material and create a finished product.

Another popular method, CNC turning, uses a non-rotating tool that moves linearly as the piece of material rotates at high speeds. This process is perfect for creating cylindrical parts and components.

Despite the differences in process, all forms of CNC machining share the goal of creating precise parts and components from a variety of materials, one of which is magnesium.

What is Magnesium and Its Uses?

CNC machining parts

Magnesium is the eighth most abundant element in the Earth’s crust, and the third most abundant element dissolved in seawater. It is a vital mineral for the human body and serves various functions in maintaining our health. However, its uses extend far beyond biology and into the world of manufacturing and industry.

This lightweight metal boasts several desirable characteristics that make it an excellent choice for numerous applications. Magnesium is strong yet incredibly lightweight, making it perfect for industries like aerospace, where weight reduction without compromising strength is a crucial requirement.

Furthermore, its excellent heat dissipation properties make it an ideal candidate for the electronics industry, specifically for devices like laptops and mobile phones that generate significant amounts of heat. Military and medical sectors also favor magnesium for its non-toxic nature and resistance to radiation. Industries like agriculture, lighting, and automation, too, have diverse applications for this versatile material.

Given these numerous benefits, it’s not surprising that industries are interested in CNC machining of magnesium. But the question remains, can you actually CNC machine magnesium? Let’s find out in our next section.

Can You CNC Magnesium?

The answer is a resounding yes. Magnesium, despite its unique properties, can be processed using CNC machining techniques, much like other metals. The key lies in understanding the material’s characteristics and adapting the machining process to get the best results.

One of the significant advantages of magnesium is that it is very machinable. In other words, it can be easily cut, shaped, and finished using CNC machines. Its lightweight nature and excellent machinability make magnesium a favorite among manufacturers looking to achieve precision components with less energy consumption.

At Worthy Hardware, we employ advanced CNC equipment capable of machining a wide range of materials, including magnesium. Our expert team has extensive experience and a deep understanding of how to adjust tooling, speed, and other parameters to produce high-quality magnesium components with precision and efficiency.

How Hard is it to Machine Magnesium?

Machining magnesium is actually easier compared to many other metals. Its inherent lightness and excellent machinability make it less strenuous on CNC machines and cutting tools, resulting in less wear and longer tool life.

While magnesium is easier to cut, this doesn’t mean the process is without its complexities. Just as with other materials like aluminum, brass, copper, stainless steel, and titanium, machining magnesium requires specific techniques and precautions to ensure a smooth, efficient, and safe process.

What Type of Cutting Fluid is Recommended for Milling Magnesium?

When machining magnesium, the choice of cutting fluid is crucial due to the material’s high chemical reactivity and flammability. Not all cutting fluids are suitable for use with magnesium, and using the wrong one could potentially lead to dangerous situations.

As a general rule, the best cutting fluids for machining magnesium are those that don’t contain water. Water-containing cutting fluids can react with magnesium chips or dust, producing hydrogen gas, a volatile substance that can lead to fire hazards.

Oil-based or petroleum-based cutting fluids are usually recommended because they do not react with magnesium and can effectively cool and lubricate the machining process. However, it is essential to remember that any kind of fluid, if ignited, can burn, so it is crucial to employ safe practices during the machining process.

At Worthy Hardware, safety is our top priority, and we follow rigorous procedures and best practices for machining magnesium and other flammable metals. This includes appropriate selection and usage of cutting fluids and regular cleaning to avoid the accumulation of magnesium chips or dust.

Safety Tips for Machining Magnesium

CNC machining parts

While magnesium brings many advantages to the table, its high reactivity and flammability require the utmost attention to safety during machining. Here are some crucial safety tips to consider while machining magnesium:

Use Appropriate Cutting Fluids: As previously discussed, the selection of cutting fluids is crucial. Always choose fluids that don’t react with magnesium, typically petroleum or oil-based fluids.

Maintain Cleanliness: Magnesium chips and dust can be highly flammable. Regular cleaning of the machining area and proper disposal of magnesium chips or dust is essential. Never leave magnesium chips in areas where they may come into contact with water or other reactive substances.

Proper Ventilation: Adequate ventilation is critical to disperse any magnesium dust that could be ignited.

Prohibit Smoking and Open Flames: Given the flammable nature of magnesium, the machining area should be a strictly no-smoking zone. Open flames and sparks must also be strictly prohibited.

Fire Safety Measures: Always have Class D fire extinguishers readily available in areas where magnesium is machined or stored. It’s crucial to remember that magnesium fires can’t be extinguished using water or a standard fire extinguisher. In fact, water can exacerbate the situation as it reacts with burning magnesium to produce hydrogen, a highly combustible gas.

Appropriate Training: All operators involved in machining magnesium should be adequately trained on safety protocols and how to respond in case of a fire. Remember, knowledge and preparedness can significantly mitigate risks.

Safety Gear: Operators should wear safety gear, including safety glasses, gloves, and fire-resistant clothing.

Avoiding Tight Clearance Angles: When machining magnesium, it is crucial to avoid tight clearance angles. This is because machining with tight clearance angles often results in the formation of longer, unbroken chips which can pose significant safety risks.

These longer chips can easily entangle with the rotating parts of the machine, leading to possible equipment damage and worker injury. Moreover, due to magnesium’s flammable nature, these chips can also pose a serious fire hazard if they start to heat up.

Therefore, it’s best to use tools with larger clearance angles. This reduces the contact between the tool and the workpiece, leading to lower heat generation and smaller chip sizes, thereby minimizing the risk of fire.

Making Discontinuous Chips: Discontinuous chips, as opposed to continuous ones, break off frequently during the machining process. This prevents chip entanglement, reduces heat buildup, and minimizes the risk of ignition.

To achieve this, you can adjust cutting conditions, like reducing cutting speed or feed rate. Selecting appropriate tool geometry and using sharp cutting tools can also promote the formation of discontinuous chips. Furthermore, using suitable cutting fluids can also help cool the process and reduce the chances of the chips igniting.

Why is Magnesium So Hard to Put Out?

CNC machining parts

Magnesium is notorious for being challenging to extinguish once ignited. But why is that the case? The answer lies in the very nature of magnesium’s chemical properties.

When magnesium burns, it reacts with oxygen to form magnesium oxide and, in the process, releases a significant amount of heat. This reaction is exothermic, meaning it generates heat, making the fire self-sustaining as long as there’s enough magnesium and oxygen.

But there’s another critical aspect that makes magnesium fires especially tough to handle. When you try to extinguish a magnesium fire with water, the heat of the fire breaks the water down into hydrogen and oxygen. The oxygen fuels the fire, while the hydrogen, a highly combustible gas, can potentially cause an explosion.

Thus, conventional firefighting methods using water or carbon dioxide are ineffective and potentially dangerous. Instead, specialized Class D fire extinguishers, which contain dry powder extinguishing agents, are used to combat magnesium fires.

Remember, the best way to deal with a magnesium fire is to prevent one. Adhering to the safety tips mentioned in the previous section and following best practices in the machining process can significantly minimize the risk of a fire.

Is Magnesium Safe to Handle?

Magnesium, in its solid form, is generally safe to handle. It does not pose a health hazard through skin contact or inhalation under normal conditions. However, the safety issues with magnesium primarily arise when it is in the form of fine dust or shavings, which can ignite and burn intensely.

As with any machining operation, it’s important to follow safety protocols and best practices. This means proper training for all personnel involved in magnesium machining, maintaining a clean workspace, using the correct cutting fluids, and having the appropriate fire safety measures in place.


CNC machining magnesium opens up a world of possibilities for lightweight, durable, and precise components. But as we’ve discussed, it also comes with unique challenges. By understanding these challenges and how to overcome them, we can harness the full potential of this incredible material.

Whether you’re in the aerospace, electronics, military, medical, agriculture, lighting, or automation industry, we are here to provide high-quality, customized CNC machining solutions that cater to your unique needs.

Interested in learning more about CNC machining magnesium or other materials? Feel free to contact us. Our team of experts is always ready to help.


1. Are magnesium alloys very machinable?

Yes, magnesium alloys are highly machinable. They offer excellent cutting properties, resulting in good surface finish and accuracy.


2.Can magnesium be cut easily?

Yes, magnesium is relatively easy to cut due to its lower hardness compared to other metals like steel and titanium.