PURPOSE: To improve the productive efficiency of the bar stock of hot rolled tool steel having high hardness, in the long size hot-rolled tool steel worked essentially into an extruding pin, subjecting it to hardening as is in a coiled shape and thereafter executing bend removing as temporarily tempered.

CONSTITUTION: The steel of hot tool steel having a coiled shape is subjected to hardening treatment, is subjected to temporary tempering in the temp. range lower than the temp. at which secondary hardening occurs and in which retained austenite is present and is subjected to straightening. Hardening strains generated by the hardening treatment are removed by the temporary tempering, bend removing is executed without generating cracking, breaking or the like and the straightening by which the coiled shape is formed into bar stock can be executed. The steel subjected to the straightening is cut into a long size of ≥500mmL, and after that, normal tempering treatment is executed to obtain the objective long size hot rolled tool steel subjected to hardening and tempering treatment into ≥50 HRC high hardness.