PURPOSE: To manufacture the title steel products by rapidly heating steel products contg. C and one or more out of Mn, Cr, Si, Mo and other components followed by hardening, rapid heating to a specified temp., quenching, cold plastic working, reheating to a specified temp. and low temp. annealing.

CONSTITUTION: Hardenable steel products contg. C and one or more out of Mn, Cr, Si, Mo and other components are rapidly heated by high frequency induction heating or the like, hardened, rapidly heated to the temp. range of 300W600°C by a similar means, and water-quenched immediately when a desired temp. in the range is attained, thus obtaining steel products having a tensile strength above 150kg/mm2, high toughness and high workability. The products are then cold- plastic-worked, reheated at 300W500°C for 30W60min, and tempered at a low temp. to manufacture worked steel products having high strength, superior durability and superior creep resistance.