Form This specification covers a nitriding grade of premium aircraft-quality@ low-alloy steel in the form of bars@ forgings@ mechanical tubing@ and forging stock. AMS6496 and AMS6497 cover UNS K23280 with other quality levels. Application These products have been used typically for nitrided parts requiring high minimum core hardness with a narrow range@ reduced distortion and subject to stringent magnetic particle inspection standards@ but usage is not limited to such applications