Duralumin CNC Machining For Beginners: A2017, A2024, and A7075 Explained

Key Takeaways

• Duralumin alloys (A2017, A2024, A7075) offer high strength and good machinability but require surface treatment due to poor corrosion resistance.

• A2024 provides higher strength than A2017, while A7075 is one of the strongest aluminum alloys, delivering steel-like strength at much lower weight.

• A7075 is widely used in aerospace and high-performance applications, but its susceptibility to corrosion and stress corrosion cracking requires careful material selection and protective coatings.

Overview

Duralumin refers to aluminum alloys strengthened with copper (Cu) and magnesium (Mg). The most common grades are A2017 (Duralumin), A2024 (Super Duralumin), and A7075 (Ultra-Super Duralumin).

Because of their high copper content, Duralumin alloys have low corrosion resistance. When machining parts for corrosive environments, surface treatments or protective coatings are essential. Common applications include screws, aerospace equipment, gears, rivets, hydraulic components, and marine parts.

Super Duralumin (A2024)

Super Duralumin (A2024) contains more copper and magnesium than standard A2017, giving it greater strength while maintaining good machinability.

Because it has low corrosion resistance, surface treatments such as anodizing are necessary. To improve durability, a composite plate called A2024PC is used, which bonds a pure aluminum layer (A1230) to the surface.

Ultra-Super Duralumin

Ultra-Super Duralumin (A7075) is one of the strongest aluminum alloys available. It contains 1.2–2.0% copper, 2.1–2.9% magnesium, and 5.1–6.1% zinc. The addition of zinc distinguishes it from A2017 and A2024.

The name “Extra Super Duralumin” (ESD alloy) originated from earlier material development, where Duralumin (D alloy), Sander alloy (S alloy), and Zinc Duralumin (E alloy) were combined into what became known as “Extra Super Duralumin,” now commonly known as Ultra-Super Duralumin.

A7075 is valued for its steel-like strength, making it a preferred material for aircraft structures. On the Brinell hardness scale, it measures around 160 HB, compared to 58–63 HB for tool steel SKD11 and about 187 HB for stainless steels SUS303 and SUS304. While stainless steel is harder in absolute terms, A7075 delivers nearly twice the specific strength.

Like other types of Duralumin, A7075 has poor corrosion resistance and is prone to stress corrosion cracking, so careful material selection is critical. Composite versions, such as those bonded with an A7072 surface layer, improve durability.

Aluminum CNC Machining at Yumoto Electric

Yumoto Electric delivers high-quality components fast, worldwide. We provide precision machining for a wide range of metals using milling, turning, and specialized metal processing. We have experience with over 200 materials including aluminum alloys, stainless steel, molybdenum, and titanium. 

If you’re unsure about material selection or machining methods, we offer complimentary consultations to help optimize your design and production. For any questions, please feel free to contact us.