Dottie 14H234 - 1/4'' x 2-3/4'' Slotted Hex Washer Head Concrete Screw Anchor is made of carbon steel with a blue Xylan finish. It is designed for close to edge fastening in poured concrete, prestressed concrete, cinder block, brick, and mortar. Features include strong grip, corrosion resistance, and can be loosened for adjustment or removal. Packaged in a sleeve of 500, with a high-low thread type, hex head, hex/slotted drive type, and gimlet point type. Pre-drill size is 3/16'' x 4-1/2'', hex size is 5/16'', bit size is #2. The concrete screw anchor is 2-3/4'' in length, with a 1/4'' diameter.