Concrete Screw 1/4 Inch x 2-1/4 Inch Hex Head – 100 PieceAn externally threaded, hardened screw with a double lead, consisting of alternating raised and lowered threads with notches cut into the raised threads, and a diamond-shaped, nail-type point.They are designed for use in most masonry base materials, such as concrete, brick or block.Make a Pilot Hole with a 3/16″ x 4-1/2″ Concrete Screw Drill Bit. Drill Bit Not Included.100 Piece BoxAllied BoltHTAP14214