The key technology for heat treatment of the crankshaft is surface strengthening treatment. Ductile iron crankshafts are generally normalized and prepared for surface preparation. Surface strengthening treatments generally use induction hardening or nitriding. Forged steel crankshafts are journaled and rounded. The imported equipment includes AEG automatic crankshaft quenching machine and EMA quenching machine.

According to foreign data, the spheroidal graphite cast iron crankshaft is compounded with a rounded rolling process and ion nitriding to increase the fatigue strength of the entire crankshaft by more than 130%. Some domestic manufacturers have also carried out this practice in recent years and achieved good results.
For the crankshaft fillet rolling process, the machine tool produced by HEGENSCHEIDT-MFD AUTOMATIC in Germany uses the patented technology of variable pressure rolling and correction. It is a good rounded rolling device, but it is expensive. At present, domestic research in this area has also achieved certain results.