CNC (Computer Numerical Control) machining is among the most useful processes in manufacturing, allowing you to create custom parts and prototypes. For those who may not have used it, it is a subtractive process: that is, you begin with a block of material larger than the finished part you want; then several machines remove layers from that block until you’re left with the final product.

While you can choose from a variety of materials in CNC machining—steel, brass, plastics, even wood—aluminum is perhaps the most useful. One big advantage of aluminum, for instance, is that it is simply more affordable than most other materials. After all, who doesn’t care about the bottom line? In addition, though, aluminum is particularly well-suited to CNC machining, and using it results in a strong, durable finished piece.

Aluminum is Easy to Work with

You’ll find that when it comes to CNC machining, aluminum has a number of unique properties that make it especially easy to work with. For instance, aluminum is significantly softer than steel, one of the other metals commonly used in CNC. Softness means it chips quickly and easily. It also means drills go through it with no problems.

Additionally, aluminum is quite bendable, so in addition to cutting it, you can fold and press it during the CNC process, creating virtually any shape you need. And because it can be turned so easily, you can be incredibly precise, with tolerances within .025 mm.

Finally, though, aluminum accepts more custom finishing options than most other materials. It’s easy to polish, but you can also plate it, which means you can apply a variety of custom colors to the finished product.

Aluminum is Affordable

Many manufacturers choose aluminum because it is more affordable than using other materials. To begin with, you can generally purchase aluminum more cheaply than metals such as zinc or copper. It is typically more expensive than steel, but the money you save during the CNC process itself often more than makes up this price difference. Because it is so machinable, using aluminum saves time, and saving time ultimately saves money.

Aluminum is also among the most recyclable materials you can use. Reusing aluminum saves almost 90 percent of the energy required to make the metal from scratch. That’s important when you consider the CNC process. As you might expect, removing excess material to get down to the part you need can result in enormous waste. Recycling that waste not only reduces your carbon footprint but can allow you to recoup some of your initial costs.

Aluminum Produces a Durable Final Product

Of course, ease of use and affordability aren’t necessarily advantages if the end product isn’t up to quality standards. Luckily, though, using aluminum results in an especially durable product. Aluminum is lightweight and easy to work with, yet at the same time, it offers a high strength-to-weight ratio. A lightweight aluminum part can give you the same durability as much heavier parts made using other metals. This is especially true if aluminum is alloyed with other metals such as copper, magnesium, or zinc.

In addition, aluminum tends to resist corrosion better than other metals because it reacts to air by forming a thin protective oxide coating. It conducts both heat and electricity extremely well, it is resistant to cold temperatures, and it isn’t magnetic—all useful properties in machine parts.


For all these reasons, aluminum has become a go-to metal in creating parts for the military and aerospace industries. It is widely used in the design of medical equipment and is an important component of computers. While it certainly isn’t suitable for every project, CNC aluminum has a number of advantages over using other materials.

The next time you begin a project, think about how CNC and especially CNC aluminum could help you do it faster, more efficiently, and cheaper than other methods.