These Wood Screws by Prime-Line Products are constructed of steel and come in a corrosion-resistant finish, enabling them to be used both indoors and out. The threads on wood screws are designed to pull two materials tightly together. Pre-drilling is sometimes necessary where hardwoods may split without a pilot hole to drive into. The fastener head, drive type, size and grade may vary slightly between fasteners of this type, while the ease of use and gripping strength do not.