The 18-8 stainless steel self-drilling screw with plain finish has a pan head and a star drive. The 18-8 stainless steel material provides strength and offers good corrosion resistance in many environments. The material may be slightly magnetic. The pan head has a flat top and short vertical sides with a rounded top edge. The star drive, also called a Torx drive, has a six-pointed indentation that provides a large contact area for the driver, resisting slippage better than a Phillips or slotted drive. A star drive requires use of a Torx driver for installation and removal.
Self-drilling screws, a type of self-tapping screw, are threaded fasteners that drill their own hole and thread it as they are installed. Usually only recommended for use with metal, self-drilling screws are available with wings that enable use when fastening wood to metal. The drill point length should be long enough to penetrate both materials being fastened before the threading portion reaches the material.