Aluminum
A metal which is commonly used for its light weight property while still being somewhat strong. = How to Read Aluminum Alloy Designations=
Contents
Wrought Alloy Designation System
We shall first consider the 4-digit wrought aluminum alloy identification system.The first digit (Xxxx) indicates the principal alloying element, which has been added to the aluminum alloy and is often used to describe the aluminum alloy series, i.e., 1000 series, 2000 series, 3000 series, up to 8000 series (see table 1).
WROUGHT ALUMINUM ALLOY DESIGNATION SYSTEM
| Alloy Series | Principal Alloying Element |
| 1xx | 99.000% Minimum Aluminum |
| 2xx | Copper |
| 3xx | Manganese |
| 4xx | Silicon |
| 5xx | Magnesium |
| 6xx | Magnesium and Silicon |
| 7xx | Zinc |
| 8xx | Other Elements |
Fatigue Analogy: Aluminum runs short sprints while steel does marathons/
1000 Series
The 1000 series has "excellent corrosion resistance, high thermal and electrical conductivity, low mechanical properties, and excellent workability."
1100
Used in soft solid rivets
2000 Series
The 2000 series is generally heat-treated for optimum properties, and heat-treated properties can exceed mild steel. Notable alloys are 2024, the most widely used alloy in aircraft, and 2117, which is used in solid rivets.
2024
3000 Series
The 3000 series is best for non-structural uses. 3003 is a notable alloy for being easy to weld.
3003
3003 is 20% stronger than the 1000 series but is about as workable as pure aluminum. It can be TIG or gas welded, and is non-heat treatable. 3003-H14 is malleable and weldable. (<a href="https://www.oldcarsweekly.com/restoration/metalworking-101-fundamentals-of-fabrication">https://www.oldcarsweekly.com/restoration/metalworking-101-fundamentals-of-fabrication</a>)
5000 Series
5000 series alloys are used for tanks and fluid lines, and are moderate- to high-strength nonheat-treatable.
5xxx
6000 Series
The 6000 series has medium strength and good formability and corrosion resistance. A notable alloy is 6061.
6061-T6
High strength but somewhat brittle, hard to weld and may create stress cracks at the weld.
7000 Series
The 7000 series can be high-strength, with a notable alloy being 7075.
7075-T6
7075 is one of the strongest aluminum alloys and is frequently used in aerospace and automotive applications where both strength and weight are critical. The largest downside is that welding 7075 is not weldable.
