Assortment- Hex Head Tek Screw 655 pcs #6-#20 in PB32Sold in sets of 1 Tek Screws, also called self drilling screws, are a type of multifunctional fastener. These screws drill their own pilot holes as you insert them. Tek screw design features a pointed drill bit at the screw's tip, so as you drill in the screw, it easily carves into a solid material surface and spins into place. Tek screws are ideal for screwing through materials without pre drilling, so you can attach wood, metal and composite pieces