Self-drilling screws, also referred to as tek screws or self-tapping screws, have a drill bit point on the bottom of the fastener.  The drill bit point eliminates the need for separate drilling and tapping installations.  The self-drilling screws can be installed into steel materials up to ½” thick.  Self-drilling screws create their own hole and form their own mating thread in the process.  Self-drilling screws are used to fasten together steel or other metals and are typically used to join materials like sheet metal. The TEK number of the tip distinguishes the screws drill bit length.