The American Iron and Steel Institute (AISI) classification system has designated the letter ‘P’ to refer to mold steels or Group P steels. The main alloying elements in the mold steels are chromium ...
Mold steels are designated as group P steels according to the AISI classification system. These steels include one medium carbon steel and all low-carbon P-series tool steels such as P2, P3, P4, P5, ...