The huge part of details’ nomenclature used in aerospace industry, is manufactured by the sheet-metal stamping method. The main issue of the sheet-metal production in aerospace industry is low and hardly predictable durability of stamping rig. The tool steel disintegration character is very important as well as construction features of the tool and equipment. The article presents the results of studies of the mechanical and magnetic characteristics of Х12МФ tool steel. It is shown that the investigated steel in a state specified by the GOST is destroyed by a brittle mechanism. A series of experiments for this steel was carried out for the first time and the data obtained are unique. They will make it possible to develop recommendations for increasing the durability of punching tools used in the aerospace industry, and to increase the tool life prediction precision. © 2021, Univelt Inc. All rights reserved.