Abstract: A material for steel wool is disclosed which essentially consists of 0.05 to 0.20% of C, up to 0.10% of Si, 0.50 to 1.30% of Mn, 0.035 to 0.10% of P, up to 0.04% of S,0.05 to 0.15% of N and the balance Fe. In this material, Al.sub.2 O.sub.3 inclusions with sizes not smaller than 3 microns are suppressed to a level not greater than 20 ppm and when the content of the Al.sub.2 O.sub.3 inclusions (3 microns and over) is in the range of 5 to 20 ppm, Al.sub.2 O.sub.3 inclusions with a size ranging from 3 to 10 microns is contained in an amount not smaller than 30% of the total content of Al.sub.2 O.sub.3 inclusions with sizes not smaller than 3 microns.

Abstract: A steel for machine construction having excellent cold forgeability and machinability, the steel having a composition of below 0.6% C, below 0.35% Si, below 1.65% Mn, below 3.5% Ni, below 3.5% Cr, below 0.35% Mn, 0.010-0.10% Al and below 0.002% B, the rest being Fe and impurities with limited contents of Ca in the range of 0.0005-0.05%, S of below 0.12% and Al.sub.2 O.sub.3 inclusion of below 0.002%.