This document, as referenced in the applicable product specifications in procurement documents, contains: a. A catalog of the standard carbon steels, alloy steels (including H-steels), and stainless and heat-resisting steels that are designated by chemical composition, or (for H-steels) by chemical composition and hardenability limits by reference to standard industry documents. b. Rules for designating the chemical content of carbon steels, alloy steels, and stainless and heat-resisting steels that are not classified as standard.
AIR4127 covers methods to classify steels based on composition and hardenability, replacing AMS-STD-66 and FED-STD-66.