Best Aluminum for Machining: Choosing the Right Grade

In an ideal world, you’d have the knowledge of a metallurgist and hands-on machinist experience anytime you needed to choose the right aluminum grade for a specific machining process, including CNC machining. The inherent characteristics of aluminum alloy make it relatively easy to machine, but not all aluminum alloys are like that. Various aluminum grades differ in their overall machinability and use. Some of the most commonly used aluminum alloys in machining are MIC 6, 2024, 5083, 6061, 7050, and 7075 aluminum alloys.

Ultimately, the best aluminum for machining is directly related to the purpose or application of the component being machined. Before choosing the aluminum alloy grade for your machining process, review the key characteristics, machinability, and typical applications of common aluminum alloys.

2024 Aluminum Alloy

Characteristics: High strength with excellent fatigue resistance but poor corrosion resistance.

Machinability: It produces uniform chips but is prone to chipping at the end of heavy cuts where the tool breaks out. To prevent this, modify the toolpath to ease the tool exit. It machines to a high finish.

Applications: Aerospace—whenever a high strength-to-weight ratio is required or the component is under tension.

5083 Aluminium Alloy

Characteristics: This aluminum alloy performs well in extreme environments such as seawater and industrial chemicals. It has the highest strength of non-heat-treatable aluminum alloys, lower hardness, and retains outstanding strength after welding.

Machinability: High strength limits the complexity of machined components—poor machinability results in surface roughness.

Applications: Rail cars, pressure vessels, dump truck bodies, and marine applications such as marine vessels. Not recommended for use in temperatures over 150°F (65°C).

6061 Aluminium Alloy

Characteristics: One of the most versatile heat-treatable alloys. These aluminum alloys have excellent corrosion resistance.

Machinability: These machinable aluminum alloys have exceptional machinability. The harder the temper, the easier the machining.

Applications: Structural, general, and electrical applications. One of the most commonly used aluminum alloys for common applications for its mechanical properties, such as high thermal conductivity and electrical conductivity.

7050 Aluminium Alloy

Characteristics: It is heat-treatable, has high toughness, maximum yield strength, and good corrosion resistance even at subzero temperatures.

Machinability: 7050 aluminum alloys have better machinability than 7075, though 7075 has less burr formation and better surface quality.

Applications: Ideal choice for aerospace applications and heavy plate components because of its mechanical properties.

7075 Aluminium Alloy

Characteristics: One of the highest-strength aluminum alloys available, extremely stiff, excellent strength-to-weight ratio, heat treatable, and lower corrosion resistance.

Machinability: Fair, in comparison to 6061 aluminum alloy. Smooth but dull gray finish.

Applications: Aerospace, highly stressed components, bike frames, etc.

MIC 6

Characteristics: Outstanding dimensional stability and flatness, low internal stresses, and minimal contaminants and porosity.

Machinability: Excellent machining processes, allows high-speed metal removal with minimum distortion, and produces small, uniform chips.

Applications: Base plates, templates, jigs, gauges, molds, dies, routing tables, chip printers, vacuum chucks, electronics, and automotive and aerospace components.

Choosing an Aluminum Grade That’s Right for Your Machining Process: At a Glance

Because of its versatility, exceptional corrosion resistance, good workability, and ease of machinability (relative to ferrous metals and alloys), an aluminum alloy is used in almost every machine shop worldwide—even here in the San Francisco Bay Area. With the proper techniques, it can be machined quickly and efficiently.

• MIC 6 – Excellent Machinability (Cast plate)
• Alloy 6061 – Good Machinability (T4 and T6 tempers)
• Alloy 7050 – Fair Machinability (Better than 7075)
• Alloy 7075 – Fair Machinability (Compared to 6061)
• Alloy 2024 – Fair Machinability (Prone to chipping)
• Alloy 5083 – Poor Machinability (Surface roughness)

All grades of aluminum alloys are machinable when proper cutting tools, feeds, speeds, and techniques are carefully matched to the aluminum alloy’s characteristics and the component’s design. With the right aluminum alloy grade, you can optimize the performance of machined components, achieve the required dimensions, strength, and weight, and cost-effectively manufacture quality components.

We Have the Right Aluminum Grade for Your Machining Needs: Local and Nationwide

Industrial Metal Service offers a wide range of the most frequently used aluminum alloys. From our warehouse in San Jose, CA, to the San Francisco Bay Area, we can provide scheduled delivery to meet your production schedules or rapid delivery when you need aluminum metals in a hurry. We offer certified new aluminum metals and verified metal remnants at unbeatable prices. Additionally, our cut-to-size sawing services take care of cutting your order of aluminum metals to the required sizes, and we ship nationwide—quickly—for your convenience.

When you’ve chosen the best aluminum for machining or need assistance in making that choice, give us a call, and we’ll take care of your concerns.