Form: This specification covers a corrosion and heat resistant nickel alloy in the form of investment castings. Application: Primarily for structural parts requiring strength up to 1300??C an oxidation resistance up to 1800??(980??. 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 A~S 2280-2. Castings shall conform to Class 1 unless Class 2 is specified by purchaser.