is actually favorable that 6061 and 6063 aluminum are not especially hard, as materials that rank high on the Brinell scale tend to be brittle and shatter easily (think glass). These alloys are ductile enough to be formed yet strong enough to resist deformation, but 6061 aluminum is a better choice if hardness is a major concern.
6061-T6 6061 T6
Aluminum 6061 and Aluminum 6063 are similar in composition and mechanical properties, and both are popular for extrusions. Both alloys contain magnesium for increased strength and silicon to reduce the melting temperature. Alloy 6061, or structural aluminum, comes in two variations, or tempers, T4 and T6, which have slightly different