What's the difference between aluminum series 6000 and aluminum series 7000?

What's the difference between aluminum series 6000 and aluminum series 7000?



6000 series are alloyed with magnesium and silicon. They are easy to machine, are weldable, and can be precipitation hardened, but not to the high strengths that 2000 and 7000 can reach. 6061 alloy is one of the most commonly used general-purpose aluminium alloys.

7000 series are alloyed with zinc, and can be precipitation hardened to the highest strengths of any aluminium alloy (ultimate tensile strength up to 700 MPa for the 7068 alloy). Most 7000 series alloys include magnesium and copper as well.

7 series is much harder than 6 series and more difficult to machine - to a certain point. The thing is that it's so hard (for aluminum) that chips don't generally stick to the endmill like 6 would.