Airframe and Engine Manufacturers:

Aerospace Material Specifications (AMS)

ASTM (American Society for Testing and Materials)

Military Specifications
These are standardized documents developed by the United States Department of Defense.  
Industry commercial specifications developed by manufacturers such as Airbus, Boeing, Cessna,
McDonnell Douglas, Pratt & Whitney, GE, Rolls Royce, Lockheed, and Airbus
These are standards developed by the Aerospace Materials Division under the direction of the SAE
Aerospace Council.  Over 1200 AMSs have been adopted by the Department of Defense and are used
worldwide by the aerospace industry.
These standards are developed voluntarily by technically qualified members located worldwide.  ASTM
standards are used as reference procedures in most AMS and Military aerospace specifications.