25CrMo4 or 1.7218
C: 0.22%-0.29% Si: 0.40% max Mn: 0.60%-0.90% P: 0.035% max S: 0.035% max Cr: 0.90%-1.20% Mo: 0.15%-0.30%
C: 0.22%-0.29% Si: 0.40% max Mn: 0.60%-0.90% P: 0.025% max S: 0.020% max Cr: 0.90%-1.20% Mo: 0.15%-0.30% Ni: 0.30% max Al: 0.040% max Cu: 0.30% max