ISO/TS 4949:2016
Steel names based on letter symbols
Product Details
NOTE 1 In order to avoid ambiguity, the principal symbols established according to this document can be supplemented by additional symbols identifying additional characteristics of the steel or steel product, e.g. suitability for use at high or low temperatures, surface condition, treatment condition, deoxidation.
NOTE 2 These rules can also be applied to nationally or regionally standardized steels.