Conventional Specification for steel castings, area acceptance specifications, magnetic particle and liquid penetrant inspection “PH”: Means Precipitation Hardening, indicating a steel which might be hardened by a special heat treatment process. Grades like 17-4PH tumble into this class. NOTE: The data and data On this product or service data sheet https://madanijayateknik.com/service/detail/round-bar-plate-sheet-pipe-tube-stainless-steel-321-uns-s32100-din-x6crniti18-10-aisi-321-dan-321h-uns-s32109-din-x8crniti18-10-aisi-321h