Form

This specification covers a premium aircraft quality, low-alloy steel in the form of bars, forgings, mechanical tubing, and forging stock.

Application

These products have been used typically for critical carburized parts, such as bearings, gears, and shafts, requiring high minimum core hardness within a narrow range, good resistance to elevated temperature up to 600 °F (316 °C), and subject to rigid magnetic particle inspection standards, but usage is not limited to such applications.