Powers Hex Washer Screw Anchor, 3/4 in Dia. x 4 in, Steel, Zinc Plated Fastener Finish Box of 20 (PFM1411720). High-strength heavy-duty one-piece Screw Anchors are for use in both cracked and uncracked concrete. They can be easily installed with standard-size drill bits, and are removable, for temporary anchoring. Vibration- and shock-resistant. For use in fastening conveyors, pallet racking, racking guards, motors, bracing, piping, ladders, fencing, beams, angles, or dimensional lumber to concrete or masonry.