PURPOSE: To prevent damages owing to freezing cracks of grid bodies by pouring molten metal into metal molds in the state that they are inclined by 10W20° from a perpendicular direction thereby performing casting.

CONSTITUTION: Releasing of heat through the interface of metal molds and molten metal occurs in the direction opposite from an arrow 8 but gravity acts in the arrow 9 direction. If the metal molds are horizontal and vertical, it becomes Figs. (a) and (b), wherein gaps are produced or not at the interface 7 owing to the freezing shrinkage of molten metal and the releasing of heat becomes high or low in the respective gravity directions. With the metal molds, the heat radiation is made easier as the inclination is made higher as shown in Figs. (c)W(e), and it is sufficient if heat is completely radiated just before the grid bodies are takne out from the metal molds. To this end, the number of casting defects by the freezing cracks or shrinkage porosity of the grid bodies having been cast when the inclination is gradually increased was investigated. The results thereof revealed that the inclination of ≥10° suffices. On the other hand, at ≥20°, undue external force is exerted to the opening and closing of movable metal molds.