PURPOSE: To obtain a titled metallic mold with which the effect of mold release is expected for a few years without the labor for spraying powder on the surface of said mold by applying a composite Ni plating layer contg. ionrg, or org. powder on the surface of the metallic mold.

CONSTITUTION: A metallic mold for casting a lead grid wherein, for example, a non-engraved part is masked with a self-adhesive tape of polyester is subjected to pretreatments of degreasing, alkali washing, pickling and rinsing. The mold is dipped in a composite plating soln. prepd. by adding diatomaceous earth to an Ni plating soln. consisting of NiCl2, NaPH2O2, sodium succinate, malic acid and boric acid. The plating soln. is kept at about 97°C under thorough stirring to suspend the diatomaceous earth particles. The mold is pulled up from the soln. and is rinsed, dried and heat-treated, whereby the mold covered with the composite Ni plating layer is obtained. It is possible to improve heat conductivity according to this method.