Profile: Aspen Fasteners specializes in providing bolts, screws, nuts, washers, anchors and rivets. Square head offers bearing surface for wrenching. Screw is an externally threaded fastener capable of being inserted into holes in assembled parts. An externally threaded fastener is prevented from being turned during assembly, and can be tightened or released only by torquing a nut. We offer screws such as deck, drywall, machine, self-drilling, self-tapping, thread rolling, thumb, U-drive and drive screws.