Form: This specification covers an aluminum alloy in the form of rolled or forged rings Application: Primarily for structural machined parts where good stability is required during machining. Not recommended for fusion welding. Certain design and fabricating procedures may cause these rings to become susceptible to stress-corrosion cracking; ARP 823 recommends practices to minimize such conditions Classification: Rings covered by this specification are classified by type of mechanical stress relief as follows Type 1 - Stress-relieved by stretching (7075-T651) Type 2 - Stress-relieved by compression (7075 - T652) Either type may be supplied@ unless a specific type is ordered.