How to Grade Aluminum

The grade of aluminum helps determine its use.

When working with aluminum, it is important to use the proper grade for the job you’re doing as the grade of aluminum helps determine its use. Aluminum is graded by the manufacturer for its content and heat treatment. Aluminum grades are broken down into eight graded categories, from the 1000 series to the 8000 series. Generally the higher the grade of aluminum, the higher its quality. The grade of aluminum can affect the materials appearance, fabrication abilities, corrosiveness, welding properties, weight, and strength.

Instructions

1. Determine the requirements that you’re looking for concerning the grade of aluminum. For example, the grade of aluminum required for siding your house will be very different from the aluminum required to build parts for an aircraft.

2. Review the different grades of aluminum by series. The 1000 series is resistant to corrosion, conducts electricity and heat well, and is easy to work with. The 2000 series is commonly used in aircraft, is a strong metal but less resistant to corrosion than the other grades. The 3000 series is approximately 20 percent stronger than the 1000 series, and is non-heat treatable. The 4000 series has a low melting point and is infused with silicon, and is typically used in welding wire to join other pieces of aluminum. The 5000 series has a high degree of magnesium and is a harder variant of aluminum -- this grade is popular to use for ships due to its resistance to corrosion. The 6000 series contains magnesium and silicon, giving it medium strength, good resistance to corrosion, and machinability. The 7000 series is infused with zinc, giving it a moderate to very high strength -- this series is commonly used in aircraft frames. The 8000 series displays exceptionally high strength and connectivity, and was developed specifically for aerospace applications.

3. Choose the kind of aluminum that is right for you. For example, if you are working on a boat, then you’ll likely choose the 5000 series of aluminum. Or, if you’re making a specialized part that requires a more malleable grade of aluminum, then you’ll likely choose the 6000 series.

References

• Key to Metals: Aluminum Grades