Ulmke Metals 7000 Series Aluminium Tube
7XXX alloys are heat treatable and offer very high strengths. The Al Zn Mg Cu varieties, (such as 7075), provide the highest strength of all Aluminium alloys. The atmospheric corrosion resistance of 7XXX alloys are not as good as 5XXX or 6XXX alloys so they are often coated.
7020 is suitable for welding and 7075 is almost steel like in some properties and it is therefore useful for special high strength applications. Many high performance bicycles use 7XXX series tube.