Low-carbon sn-containing free cutting steel

PURPOSE: To obtain a low-carbon Sn-containing free cutting steel having improved machinability by automatic board by adding specific amounts of Sn and S jointly into a low-carbon free cutting steel composition. CONSTITUTION: A low-carbon Sn-containing free cutting steel contains 0.15wt% or less C, 0.02wt% or less Si, 0.6W1.55wt% Mn, 0.02W1.0wt% Sn, 0.25W0.5wt% S, 0.07W0.12wt% P, 0.01wt% or less Al, and Fe. In the steel composition, S reacts with Mn to form MnS which contributes to improvement in machinability. The Sn- containing free cutting steel has machinability equal to or more than that of the conventional lead free cutting steel and also is free of environmental pollution during the manufacturing process. Thus, the steel can be used widely in various fields. COPYRIGHT: (C)1981,JPO&Japio