PURPOSE: To cut and dislodge many castings from small diameter parts and improve productivity, by charging molten metal into a mold, which is produced by forming the small diameter parts to the junctures between product patterns and a sprue bar, then applying oscillations to the mold.

CONSTITUTION: A mold 76 of a shell shape, formed by using a wax pattern 32 brazed with product patterns 24 to a sprue bar 20 is formed with cavities corresponding to the pattern 32. The parts corresponding to junctures 34 form runners 34A and the parts corresponding to small diameter parts 36 form throttling parts 36A. The mold 76 is heated to burn the remaining wax and in the state of high temp., molten metal is charged into the mold 76 and is quickly cooled so as to attain prescribed rates of solidification. When the mold 76 is oscillated in two stages with an exciter, the mold 76 is broken by the primary oscillation and a tree-like casting is removed. Many castings are broken and dislodged in the notched parts corresponding to the parts 36A of the runners 34A by the next secondary oscillation, whereby the runners are cut efficiently.