What is the difference between 6061 and 6063 aluminum?

6061 is one of the most commonly used grades aluminum grades in the world. Whether it’s an aluminum sheet, aluminum plate, aluminum bar, or aluminum angle, 6061 is the choice for a wide range of applications, including boats, furniture, and structural applications.
So, what makes 6061 so versatile? Like with any grade, it starts with the makeup of the metal. Its major alloying elements are magnesium (1.0%) and silicon (0.6%). This makes it highly resistant to corrosion, stress, and cracking. This also means the grade features good formability and weldability.
6063 is another commonly used grade of aluminum and is often compared to 6061. Both 6061 and 6063 are made up of magnesium and silicon as their primary alloying elements, meaning they exhibit many of the same properties. The difference between 6061 and 6063 is mainly in the end use. 6063 is a common grade used for custom extrusions. Its high corrosion resistance and good formability make it one of most joinable alloys.
However, 6061 angle is the most commonly used aluminum for structural applications. In general, 6061 features higher strength (tensile strength range is 20 to 42 KSI) than 6063.