Dottie Anchoring concrete screw of size 1/4-Inch, has ceramic coated blue finish for longer endurance. This 1-1/4-Inch concrete screw featuring hi-low threads, has hexagonal head and supports slotted drive type. It has drill size of 3/16-Inch x 3-1/2-Inch. Anchoring concrete screw is perfect for use in poured concrete, pre stressed concrete, cinder block, brick and mortar.