PURPOSE: To attain the improvement of the workability in a high carbon steel without causing the deterioration in its hardenability.

CONSTITUTION: A steel contg., by weight, 0. l to 0.8% C and 0.05 to 1.01% Mn and contg. either one kind of 0.0003 to 0.010% B and 0.003 to 1.01% Al and either one kind among ≤31% Si, ≤3% Ni and ≤1% Cu and in which, as for the above C content, 1 to 80% is precipitated in the form of graphite and the balance spheroidal cementite is subjected to annealing of holding it to two temp. ranges for certain time in such a manner that it is first held under heating to 700 to 900°C for 1min and is thereafter held to the temp. range of 500 to <700°C for ≥1hr, by which the steel excellent in both workability and hardenability can be manufactured.