Form This specification covers a corrosion and heat-resistant nickel alloy in the form of investment castings. Application These castings have been used typically for structural parts requiring strength up to 1300 ??(704 ?? and oxidation resistance up to 1800 ??(982 ??@ but usage is not limited to such applications. Classification Castings conforming to this specification are classified as follows: Class 1Trace element limits conforming to AMS2280-1 Class 2Trace element limits conforming to AMS2280-2 Class 3Trace element limits do not apply Castings shall conform to Class 3 unless Class 1 or Class 2 is specified by purchaser.