Abstract: A cast cold tool is obtained through the steps of forming a casting by founding a molten steel consisting by weight percentage of 0.5 to 0.8% of C, not more than 1.0% of Si, 0.25 to 1.50% of Mn, 4.0 to 8.0% of Cr, 1.0 to 5.0% of Mo, one or both of 0.2 to 1.0% of V and 0.2 to 2.0% of Nb, opptionally not more than 2.5% of W, not more than 2.5% of Ni, and the balance being Fe plus incidental impurities, subjecting the casting to solid solution treatment to decrease primary carbides precipitated in the casting to not more than 1%, preferably to extinguish completely, and subjecting the solid-solution treated casting to quenching and tempering treatment to give predetermined toughness and hardness to the casting.

Abstract: A steel having such a good machinability that it can be directly cut without being annealed and a good induction hardenability. The steel consists essentially of C: 0.37-0.45%, Si: up to 0.35%, Mn: more than 1.0% - up to 1.5%, B: 0.0005-0.0035%, Ti: 0.01-0.05%, Al: 0.01-0.06% and the balance of Fe, the content of N being up to 0.022 and has a fine structure of ferrite crystal grain size number 6 or more as defined by JIS-G0552. In addition to the above basic composition, the alloy may further contain some optional alloying elements.The material is suitable for manufacturing machine structural parts such as drive shafts of automobiles.