1. Specification. Hand and die forgings of aluminium-zinc-magnesium-copper-chromium alloy (solution treated and artificially aged to an overaged condition) (Zn 5.6, Mg 2.5, Cu 1.6, Cr 0.22). (28th May 1976) Authors: British Standards Institution, Record Type: Book Extent: 1 online resource (8 pages) View Content: Available online (eLD content is only available in our Reading Rooms) ↗