After the attack on the USSR, on June 22, 1941, MMK obtained its first order for production of metal armour. Instructions were given to proceed to the production of blanks for live shells, and to explore the possibilities of creating specialist products for armoured tanks, which required rebuilding the production facility. The government provided a number of specialists for the development of armoured steel. The factory created an "Armour Bureau", which was responsible for the development of technology for the production of armoured steel products. By July 23, 1941, the third hearth furnace of MMK produced its first steel output for the military.