in an injection mold, there is a typical direct gate, which locates at the mold center, that is so called direct gate, it has a larger sectional area and less flow resistance. It is typically applied to single cavity molds for large and deep plastic parts, it is the sprue in a multiple cavity mold, there should be a cold-slug well design at the bottom to avoid cold slugs from flowing into a cavity, the cold-slug’s size is about 1/2 of the plastic part’s thickness.