What is core metal of plastic injection mold tooling? is it important for quality?

For shorter production runs, some plastic injection mold makers will use molds made from aluminum.  Aluminum is a perfectly reasonable choice if you will not need the

plastic injection mold to perform long-term.  However, if a project requires that a plastic injection mold lasts for several years, an aluminum mold may cost more in the long-run.  High-volume precision molds are made from hardened steel.  Steel can withstand the pressures of a long production run while still meeting close tolerances.