The rapid test method for the fatigue limit stress combined with conventional group method is used to get the contact fatigue strength of induction hardening gear made of steel alloys.The reliability-stress-life curve(R-S-N curve)is fitted according to experimental data with the twoparameter Weibull distribution and lognormal distribution.Thus the values of stress fatigue limit under different reliabilities can be respectively got
which provides basic data for the contact fatigue life and reliability design of the induction hardening gear.