Form This specification covers an aluminum alloy in the form of sheet and plate with thickness from 0.008 to 4.000 inch@ incl (0.20 to 101.6 mm@ incl)@ clad on two sides (see 8.4). Application These products have been used typically for structural use@ including machined parts subject to excessive warpage during machining@ but usage is not limited to such applications. Certain design and processing procedures may cause these products to become susceptible to stress-corrosion cracking; ARP823 recommends practices to minimize such conditions.