PURPOSE: To decrease the generation of gaseous lead and lead-contg. waste and to improve the yield of lead by hanging a prescribed amt. of lead bar in a casting mold and bottom pouring a molten steel while blowing an inert gas from a mold stool thereby converting the molten steel to the prescribed uniform lead-contg. free cutting steel.

CONSTITUTION: The prescribed amt. of the lead bar 28 is hung in the casting mold 2 and while the inert gas is blown from a blowing plug 22 of the mold stool 4, the molten steel is bottom poured from a riser port 18 into the mold. There is no setting part in the molten steel 6 poured into the mold 2 and the molten steel 6 is converted to the prescribed uniform lead-contg. free cutting steel. The generation of the gaseous lead is decreased by a method for hanging and adding the lead bar and the lead content of the waste sticking to a runner 16 and the port 18 is decreased, by which the yield of the lead is improved.