Dottie 14H314 - 1/4'' x 3-1/4'' Slotted Hex Washer Head Concrete Screw Anchor is made of case hardened carbon steel with a blue Xylan finish. Designed for close to edge fastening, it offers a strong grip and corrosion resistance. With a high-low thread type, hex head, and hex/slotted drive type, this anchor is suitable for poured concrete, prestressed concrete, cinder block, brick, and mortar applications. It features a gimlet point type, 5/16'' hex size, #2 bit size, and pre-drill size of 3/16'' x 5-1/2''. This anchor can be loosened for adjustment or removal and comes in a quantity of 500 sleeves.