Form: This specification covers a corrosion and heat resistant nickel alloy in the form of investment castings. Application: Primarily for small parts@ such as turbine blades and vanes@ requiring high strength and oxidation resistance up to 1600??(870??. Classification: Castings conforming to this specification are classified as follows: Class 1 -Trace element limits conforming to AMS 2280-1. Class 2 - Trace element limits conforming to AMS 2280-2. Castings shall conform to Class 1 unless Class 2 is specified by purchaser (See 8.3).