The Oval-Head Phillips Chrome WallDog Screws combine anchors and screws into one These screws are ideal for fastening and anchoring purposes fixtures into wallboards and masonry base materials These are self-tapping screws, thus do not require any pre-drilling These screws drive into drywall, plaster, metal, wood, brick and concrete These screws can support up to 22.7 kg in drywall, and 317.5 kg in concrete