What You Need To Know About CNC Aluminum Machining

Jack Lie CNC machining expert

Specialize in CNC Milling, CNC Turning, 3D Printing, Urethane Casting, and Sheet Metal Fabrication Services.

CNC or computer numerical control is a series of processes either used for prototyping or mass production. The processes run on a computer program and involve various operations such as turning and milling. Meanwhile, due to the versatility of the functions, aluminum is the preferred material in the manufacturing sector. Its excellent machinability and interesting thermal and mechanical properties have led to its immense popularity within the industry.
Furthermore, aluminum’s easy-to-shape property makes it ideal for drilling processes involved in CNC aluminum machining. Essentially, other lightweight metals such as magnesium and titanium alloys can’t even hold a candle to the versatility of aluminum.
It is commonly used to produce CNC automotive and other CNC parts that require heavy-duty use with a lightweight build. So, in this article, we will be looking at the five things you may not have known about CNC machined aluminum. So, here we begin.

Aluminum as a Material for CNC Aluminum Machining

Aluminum is among the lightest metals, known for its softness, malleability, tractability, and durability. Its appearance is dependent on the roughness of its surface, which causes it to appear either silver or dull gray in its pre-finished state. Moreover, it lacks magnetic properties while being a good conductor of electricity, even though its conductivity is not as good as copper on a specific cross-section area. It is non-flammable and melts at approximately 640 degrees centigrade. As far as its wide applications are concerned, aluminum is extensively used in CNC automotive, like ATV, Aerospace, and medical industries due to its light density of 2.68.

cnc aluminum machining

Aluminum Grade

Although aluminum comes in many grades used in various CNC aluminum machining processes, the choice of aluminum grade ultimately depends on your intended machining project. Aluminum is graded and ranked according to its most important and least important characteristics. In that case, aluminum grades allow you to choose aluminum with specific shapes and properties according to your requirements, as all of them are highly machinable.
Below we have discussed a few types of aluminum grades, along with their significance:

  • Aluminum 6061: It is commonly used for 5-axis CNC aluminum machining. Undoubtedly, it is said to have fantastic weldability and topical properties, which makes it highly suitable to use in extrusion processes. Alongside that, it has excellent mechanical properties with excellent corrosion resistance in extreme conditions, medium to high strength, cool anodization, bending workability, and excellent toughness.
  • Aluminum 7075: Although this grade is also better in corrosion resistance, the reason behind its popularity is its exceptional fatigue strength. However, it might be unsuitable for welding because of its expensiveness. Consequently, it remains ideal for manufacturing tough parts such as bicycle parts, fuselages, rock climbing kits, and aircraft wings.
  • Aluminum 2024: Aluminum 2024 is known for its mechanical properties like excellent wear resistance and high strength. At the same time, it has terrible resistance to corrosion and is not weldable. It is predominantly utilized in the military and aerospace industries.

CNC Aluminum Prototype

Aluminum machined prototypes are usually produced by considering various alloys. Almost all of these alloys provide high strength with a low-density build. The most commonly used aluminum alloy is the 6061-T6 since it is ideal to utilize in electronics, transportation, aerospace, and military industries, to name a few. Typically, CNC aluminum machining operations of prototypes have an excellent tolerance to control, let’s say 0.001MM, along with manufacturing one-of-a-kind, high-quality aluminum prototypes. Likewise, CNC milling is simply the best option because of the benefits provided by the machining process resulting in high accuracy and milling aluminum.

CNC Aluminum Machining: Parts and Components

CNC machined aluminum manufactures different CNC parts and components applicable to various services, like turning, milling, and grinding. Unquestionably, there is now a steady rise in the popularity of well-machined CNC aluminum parts in the engineering sector. Given below are some of the CNC machined aluminum parts and components:

  • Front panels
  • Dowels pins
  • EMI-Housings
  • Spline shafts
  • Medical devices
  • Lighting fixtures

Avoiding Deformation in CNC Aluminum Machining

Despite being an industry favorite, aluminum suffers from a severe flaw. The alloy deforms when machined into a thin portion due to its relatively low hardness and high thermal expansion. Nevertheless, numerous precautions can be taken ahead of time to avoid material deformation.
Symmetrical CNC Aluminum Machining
It is critical to prevent extreme heat concentrations but instead produce heat dispersion or dissipation mechanisms to minimize the rate of thermal deformation.
Stratified Multiple CNC Aluminum Machining
Having numerous cavities on the aluminum alloy plate results in twisting one cavity wall due to force distribution. To prevent this from happening, ensure you process all cavities simultaneously.

Ensure a Suitable Cutting Parameter

The amount of cutting back depth has a significant impact on the cutting parameter. But then again, a CNC milling operation can solve the matter by increasing the machine’s speed and decreasing the cutting force while maintaining efficiency and reducing the number of cuts.

Drilling & Milling

When a milling cutter is used on a cavity, the cutting becomes sufficient, prompting cutting heat, deformation, and expansion. However, the most accessible approach to avoid this issue is to pre-drill with a larger tool than the milling cutter before inserting the milling cutter and milling.

5-Axis CNC Aluminum Machining

In the 5-axis machining procedure, the CNC operates while concurrently cutting in five angles of the axis. In the interim, the process is rapid and dependable for designing intricate pieces. For the record, 5-axis CNC aluminum machining has been adopted due to the following reasons:

  • The setup remains a single one, which lowers the lead time and improves efficiency.
  • It gives better geometry by avoiding collisions with the tool holder, slanting the table/tool.
  • Cutting pieces do not travel through multiple workstations, so errors are minimized, precision or accuracy is maintained, and high-quality is ensured.
  • It can utilize small-sized tools that are more rigid. Some of them are with high spindle speeds achieved by lowering the load on the cutting tool.


In conclusion, we discussed the various CNC machined aluminum procedures that a pre-finished aluminum piece goes through to transform into the finished product. Remember that it refers to a laborious process that demands experience, precision & accuracy, and robust machinery. Without question, it is due to the varying aluminum alloys employed. On the other hand, aluminum offers several notable benefits, including a rapid cutting process and high-quality outcomes. In addition, industries are swarming with professionals to fulfill your demands; however, do your homework and obtain samples to ensure the quality of the CNC aluminum.

Let our friendly and professional engineers can quickly answer any questions you have about CNC machining aluminum today!