Let’s dive in — see how a CNC machined 42CrMo4 alloy steel automotive steering shaft is made: induction hardening at spline and bearing zones to HRC 55-60, CMM-verified 0.005mm runout, shot peening for fatigue life, and DIN 5480 spline cutting. We also show matched mold design for rubber gaiters and plastic bearing cages. A clear process walkthrough for B2B buyers.