Back Home / Fasteners / Socket Products / FLAT HEAD SOCKET CAPSCREW UNC PLAIN 5/16″-18 X 1″ FLAT HEAD SOCKET CAPSCREW UNC PLAIN 5/16″-18 X 1″ SKU: X5618X1FHC Categories: Fasteners, Socket Products Made from alloy steel. Similar in design to socket head cap screws, but with a countersunk flat head. Used when a flush mounting, where a high strength screw is required. Plain black finish. Diameter: 5/16-18″ Case Quantity: 100 Log In For Pricing