7075 Aluminum is an aluminum alloy with zinc as the primary alloying element. It is very strong with strength comparable to many steels, and has good fatigue strength and average machinability, but has less resistance to corrosion than many other Aluminum alloys. Its relatively high cost limits its use to applications where cheaper alloys are not suitable. 7000 series alloys such as 7075 are often used in transport applications, including marine, automotive and aviation applications, due to their high strength-to-density ratio. Due to its strength, high density, thermal properties and its polishability 7075 is widely used in mould tool manufacturing. 7075 has been sold under various trade names including Zicral, Ergal and Fortal Constructal.