Self Drilling Anchors ScrewsAnchors Screws Owing to the high hardness, sturdy texture, and durable property, this self drilling expansion screws set can be used as a practical tool for fixing the drywall, slate, wallboard, and plasterboard. Due to the excellent design of this self drilling Expansion Screws set such as easy operation, expansion function, sharp head, and special serrated design on both sides, it can give you great convenience in attaching and removing screws on