Abstract: The invention relates to a process for the production of very hard armour plates from steel slabs, wherein the slabs are hot rolled to a final thickness above 50 mm and then hardened and possibly tempered. The characterizing feature of the invention is that a continuously cast slab is produced from a steel having0.25 to 0.32% C0.05 to 0 75% Si0.10 to 1.50% Mn0.90 to 2.00% Cr0.10 to 0.70% Mo1 20 to 4 50% Ni0.01 to 0.08% Almax 0.015% Pmax 0.005% Smax 0.012% Nresidue Fe, including usual impurities,the slab then being heated to a temperature of 1150.degree. C. or higher and heated through, whereafter following cooling in air and by the spraying of its two wide sides with pressurized water, the slab is hot rolled with a surface temperature in the range of 1050.degree. to 900.degree. C. in shaping passes having an individual deformation of .epsilon..sub.h >0.1 and with a shape factor SF>0.40 to the final thickness.