Zinc coated Kreg screws are recommended for a wide variety of indoor projects where exposure to moisture is not a significant concern. Kreg screws are constructed of highly durable case hardened steel for the strongest possible joint. The unique design of the self-tapping tip acts as a pilot to drill its own hole in the mating workpiece to prevent your material from splitting. Only Kreg screws are specifically designed to use with your Kreg Jig® to yield the strongest pocket hole joint possible.