Abstract: The invention relates to steel for hot tooling, the composition of said steel being made up of the following weight percentages: 0.30%=C=0.39%, 4.00%=Cr=6.00%, traces=Si=0.50%, traces=Mn=0.80%, traces=W=1.45%, traces=Co=2.75%, 0.80%=Ni=2.80%, 1.50%=Mo=2.60% with 1.50%=Mo+0.65W=3.20%, 0.55%=V=0.80%, with 0.65=K=0.65, where K=K2?K1 and K2=0.75×(Ni 0.60), K1=1.43×(V0.40)+0.63×[(Mo+0.65W) 1.20], traces=Al=0.080%, traces=S=0.0040%, traces=P=0.0200%, traces=Ti=0.05%, traces=Zr=0.05%, traces=Nb=0.08%, traces=N=0.040%, 10P+As+5Sb+4Sn=0.21%, traces=O=30 ppm, the remainder being iron and inevitable impurities. The invention also relates to a part produced from said steel, to the method for the production thereof, and to the use of the same.

Abstract: The invention relates to a tool steel composition comprising, expressed in weight percentage: C 0.3%-0.4% Cr 2.0%-4.0% Mo 0.8%-3.0% V 0.4%-1.0% W 1.5%-3.0% Co 1.0%-5.0% Si 0 %-1.0% Mn 0 %-1.0% Ni 0 %-1.0% the balance being mainly constituted by iron and inevitable impurities, and also to a method of preparing the composition.