Everything You Need to Know About CNC Machining Aluminum

Aluminum is one of the most highly sought-after CNC materials, as it’s well-suited for creating custom metal parts and prototypes such as brackets, base plates, and heat sink enclosures. Aluminum offers excellent machinability and can be heat-treated to high strength and hardness. 

However, no two aluminum alloys are the same. It is often a challenge for manufacturers and fabricators to identify the most suitable aluminum for CNC machining without compromising end quality or exceeding budget. 

Below, we briefly discuss some of the most commonly used CNC aluminum alloys and learn about their favorable properties and application areas.

Common CNC Aluminum Alloys With High Corrosion Resistance

Choosing the right grade aluminum for aluminum CNC machining involves analyzing several factors in parallel, such as tensile strength, high corrosion resistance, weldability, machinability, and workability. Each grade has been metallurgically engineered for some specific application areas. Aluminum alloys are widely used in various industries due to their excellent properties. 

Let’s analyze some highly popular aluminum alloys that undergo CNC processes such as milling, turning, and multi-axis machining to produce useful machine parts and prototypes for various industries. Custom aluminum machined parts can be tailored to meet specific requirements.  

6061

6061 is one of the most widely used aluminum alloys. It is lightweight and offers a clean surface finish. It’s also much easier to machine and weld than 7075 for a wide range of structural applications. 

6061 is mostly preferred for corrosion-prone low-budget applications where frequent welding is required. This explains why manufacturers consider 6061 as the go-to aluminum for most machine parts. Aluminum CNC machining of 6061 is common due to its versatility. 

However, not all 6061 alloys carry similar properties. Thus, understanding the machining properties of different 6061 aluminum grades is essential for choosing the right grade for CNC machining parts for the end application. The natural corrosion resistance of 6061 makes it suitable for various environments.

Applications:

• Aircraft parts
• Structural parts
• Cylinder heads
• Pipes
• Electronics
• Recreation equipment

6082

6082 offers excellent high corrosion resistance and exhibits the highest strength amongst all 6xxx series alloys; therefore, it’s an ideal alternative to 6061 alloys and is best suited for stressed applications. Custom aluminum machined parts made from 6082 are often used in demanding environments.

However, because it’s available in different grades, it’s important to select the grade appropriate for the end application. For instance, the most popular L grades (L111, L113, L114, L115) are used in aerospace and military applications.

Applications:

• Trusses
• Bridges
• Cranes
• Transport applications

7075

Zinc is the primary alloying element in 7075; thus, it offers the highest strength-to-weight ratio compared to any other aluminum alloy and is twice that of 6061 alloys. 7075 is widely used for aircraft and aerospace applications. Aluminum CNC machining of 7075 requires specific expertise due to its unique properties.

However, the mechanical properties vary by temper. The T6 temper has the highest strength but the lowest stress corrosion resistance; therefore, in high-stress applications, the T73 or T76 alloys are more suitable. A local metal supplier can assist you in selecting the right temper of 7075 depending on the end application. The wear and corrosion resistance of 7075 can be enhanced through proper heat treatment.

Applications:

• Gears
• Shafts
• Valves
• Mould tool
• Missile parts

2024

2024-T4 exhibits an exceptional strength-to-weight ratio coupled with high fatigue resistance, thus it’s suitable for aerospace applications.

However, it is highly susceptible to environmental corrosion. Though 2024 alloys can be forged and hot worked (T3, T4, and T8 tempers), they are not ideal for welding and soldering.

Applications:

• Commercial & military aircraft
• Automotive components
• Structural parts
• Electronics

5052

5052 is a medium- to high-strength alloy from the 5xxx series, with a strength slightly higher than 5251 alloys. The H32 hardened 5052 aluminum alloy offers excellent corrosion resistance to caustic environments in the absence of copper from its configuration.

Additionally, the high concentration of magnesium offers corrosion resistance from toxic chemicals, such as concentrated nitric acid, ammonia, and ammonium hydroxide. Though 5052 alloys cannot be heat-treated like 7075 or 6061 alloys, they can be cold worked to increase their strength.

Applications:

• Pressure vessels
• Kitchen appliances
• Hydraulic tubes
• Small boats
• Electronic chassis, tubes

5080

5080 is a homogenized and stress-relieved aluminum cast plate for high precision applications. It is a low-cost alternative to MIC-6, yet it comes with a very fine grain porosity-free structure. As a result, 5080 offers predictable tolerances and excellent dimensional stability.

Also, it allows you to work with thinner plates to optimize costs and save processing time.

Applications:

• PCB substrate
• Gages
• Fixtures
• Molds
• High precision machined components

MIC-6

MIC-6 is a 7xxx series aluminum alloy with zinc as its major alloying element. As a cast product, it is fully stress-relieved and allows for high-speed metal removal with little to no distortion, unlike other long-grained metal alloys. MIC-6 can be considered an ideal replacement to 6061 when high strength is not the primary requirement.

The granular cast structure contributes to its improved dimensional stability and smooth flatness tolerance as compared to 6061 alloys. When machined, MIC-6 produces small, uniform chips and offers good weldability and high resistance to corrosion cracks.

Applications:

• Tooling
• Base plates
• Jigs and fixtures
• Optical industry

Top-Grade Aluminum for Every Purpose and Industry
New Aluminum Plate 6061	New Aluminum Rectangular Bar	All Aluminum Shapes
Customizable thickness: Measure in inches. You can get various options for all industry applications.Can be cut to specific shapes and sizes: Excellent weldability to cater to unique project needs. Corrosion resistance: Grades like 6061-T651 are perfect for marine hardware applications that require superior rust resistance.	Environmental resilience: Due to its heat treatable nature, 6061 aluminum does well in extreme conditions.Wide selection of sizes and dimensions: Choose your sizes based on tensile strength, width, and weight. Good machinability: It’s lightweight and high strength makes it flexible for a number of applications.	Reliable supply: Consistent, certified aluminum stock you can trust.High-quality material: Superior-grade aluminum for precision needs. Custom cuts: Accurate cuts down to thousandths of an inch.
CHECK PRICE	CHECK PRICE	BROWSE ALL

Anodizing Options for Aluminum CNC Machining

In CNC machining, especially when machining aluminum, anodizing is a crucial finishing process that enhances the mechanical properties and appearance of aluminum parts. Among the different types of anodizing for aluminum CNC machining, there are three that stand out. 

Pure aluminum is often used as a base material due to its excellent electrical conductivity, but various alloys are created by adding a main alloying element to enhance specific properties.

• Type I-chromic acid anodizing: Often used in the aerospace industry, this type provides a thin yet durable coating, making it ideal for welded parts and assemblies. It’s a primer choice before painting due to its non-conductive nature and adds to the corrosion-resistant qualities of the aluminum grade.
• Type II-sulfuric acid anodizing: This type is harder than Type I and is commonly used in consumer products and automotive parts. Its durability makes it suitable for items like motorcycle parts and hydraulic valve bodies, where a balance of strength-to-weight ratio is crucial.
• Type III-hard anodize or hard coat: Known for providing the thickest and hardest coating, it’s widely used in heavy-duty applications with high wear resistance. This type is ideal for automotive, military, and marine applications, enhancing the aluminum’s strength and durability.

These anodizing types are integral to the CNC aluminum machining process, enhancing the aluminum’s corrosion resistance and strength, which is vital for the manufacturing process. CNC machines using the right cutting tool can significantly benefit from these anodizing methods, ensuring the longevity and performance of CNC aluminum machining components.

Here’s a comparison table to illustrate the differences between the anodizing types used in CNC machines:

By understanding these types in aluminum CNC machining, manufacturers can optimize the machining process and choose the best anodizing method based on the intended use and required mechanical properties of the CNC machining aluminum parts.

Purchase Aluminum for CNC Machined Aluminum Parts from a Reliable Metal Supplier

Industrial Metal Service has been supplying and recycling metals in the San Francisco Bay Area and nationwide for more than two decades. Our inventory includes a wide range of popular grades of aluminum, including 6061, 5080, and MIC-6, cut-to-size for immediate CNC machining requirements. We also supply other metals, such as titanium, steel, and copper.