Customized 42CrMo alloy steel motor shafts for a domestic new force vehicle enterprise, with 0.002mm runout tolerance and Ra0.8 surface roughness, passed 1000-hour fatigue test. 50,000 pcs/month capacity, adapted to two main models, replaced imported products with 40% cost reduction, zero quality complaints for 18 consecutive months, selected as the enterprise’s annual excellent parts project.