In terms of strength, 6061 aluminum generally has higher mechanical properties compared to 6063 aluminum.  6063 vs 6061 strength:

1. Tensile Strength: The tensile strength of aluminum refers to its ability to withstand pulling forces without breaking. 6061 aluminum typically has higher tensile strength than 6063 aluminum. The tensile strength of 6061 can range from 124-290 MPa (18-42 ksi), while 6063 typically ranges from 124-186 MPa (18-27 ksi).

2. Yield Strength: Yield strength refers to the stress at which a material begins to deform plastically without fracturing. 6061 aluminum generally has higher yield strength than 6063 aluminum. The yield strength of 6061 can range from 55-240 MPa (8-35 ksi), while 6063 typically ranges from 55-152 MPa (8-22 ksi).

3. Ultimate Strength: The ultimate strength of a material represents the maximum stress it can withstand before fracturing. 6061 aluminum tends to have higher ultimate strength compared to 6063 aluminum. The ultimate strength of 6061 can range from 152-310 MPa (22-45 ksi), while 6063 typically ranges from 152-186 MPa (22-27 ksi).

It's important to note that these strength values can vary depending on the specific temper (heat treatment) applied to the aluminum and other factors such as alloy composition, extrusion process, and the presence of any alloying elements.

While 6061 aluminum generally offers higher strength, 6063 aluminum compensates with its superior formability and workability. Therefore, the choice between the two alloys depends on the specific requirements of the application, considering factors such as strength, formability, corrosion resistance, and other mechanical properties.