The industrically special quenching method for the 13% chormium stainless steel, which is widely used for the turbine blade in Japan, was reported. By passing a heavy current of 1, 000 to 2, 000 amps., the rolled turbine blade, due to its high electrical resistance, was raised to a high temperature which caused the metal to expand.When the thermal deformation above the critical points Ac 1-3 reached the pre-calculated quenching temperature, the heatinge current was automatically cut-off and the quenching was simaltaneously carried out.By means of the new process the measurement of quenching temperature with a pyrometer no longer necessary, and the aeeurate and rapid quenching always ensured. Comparing the proposed quenching method with the usual, some advantages were summarized as follows:1) In spite of the high temperature quenching, it is free from surface decarburization and from surface scaling.2) The product reveals an excellent finish.3) The quenching temperature is imcomparablly accurate on account of the direct resistance heating.4) A produet with higher mechanical properties such as greater fatigue limit and ductility, isobtained. For example:Proof Stress Tensile Elongation Reduction Fatigue Limit(0·2%) Strength (4) of Area ×107As quenched 100kg/mmmm2 140kg/mmmm2 20% 55% -kg/mmmm2As tempered 60 74 28 60 48·55) Thc present method is applied to the round bars, sections and tubes of common and special steels. Especially it is suitable for the thin and long sections or for the intricate profile with a uniform section.6) The initial and maintenance costs of the present quenching appara us are very small.7) The operation is simple and very rapia, giving a very high thermal efficiency of about 80%).It was concluded that the new quenching method is commercially payable from the standpoint of economy and efficiency.