7075 Front-Rear Hinge Pin Brace

7075 aluminum alloy's composition roughly includes 5.6–6.1% zinc, 2.1–2.5% magnesium, 1.2–1.6% copper. It has excellent mechanical properties and exhibits good ductility, high strength, toughness, and good fatigue resistance. Highly useful in applications to allow for weight savings over steel. 

The first 7075 was developed in secret by a Japanese company, Sumitomo Metal, in 1935, but introduced by Alcoa in 1943 and was the world's first mass-production usage of the aluminum alloy for the Mitsubishi A6M Zero fighter. Later standardized for aerospace use in 1945  and used for airframe production in the Imperial Japanese Navy.