Square pan head tapping screws are designed with sharp cutting threads to create threading where needed without pre-drilling a hole. Tapping screws are used mainly in sheet metal, wood, and plastic applications. Pan Heads have a rounded top, cylindrical sides and a flat bearing surface for any area that requires general purpose bearing. Pan Head screws can be substituted for round, truss, or binding heads in most applications. The square drive allows for more grip, which decreases chance of stripping the head. Square drives also requires a square allen wrench to prevent tampering. NutsandBolts.com also stocks other similar screws such as: concrete screws, sheet metal screws and machine screws.