PURPOSE: To prevent the cementation and obsolete of cooling pipe and improve its cooling function by integrating the cavity part of the precast body and the cooling part with insert metal.

CONSTITUTION: First, the body member 1 having the specified cavity part 2 is cast by cast iron or cast steel. This cavity part 2 assumes a similar figure slightly larger than a cooling pipe 3 in the buried position of said cooling pipe. Next, the cooling pipe 3 is held in the specified position in the cavity part 2 and molten metal 5 of a melting point lower than that of the cooling pipe 3 and heat conductivity higher than that of the body member 1 is poured in the spacing in the remaining caivity 2. Thereby, the cooling pipe 3 is inserted and is integrated together with the body member 1.