SAE AMS2649C

This specification establishes the requirements for etch inspection of bare high-strength low-alloy steel parts having tensile strength of 180 ksi (1241 MPa) and higher and of carburized parts to detect overheating caused by abusive machining or grinding in the heat treated condition, and to detect localized discontinuous carburization. This process is not applicable to surface hardened steels produced by nitriding or carbonitriding. This process may remove 0.0001 to 0.0005 inch (2.5 to 12.7 micrometers) from the surface of the part.