Bronze Star 5/20" Construction Lag Screws are designed for use with deck ledger boards, log homes, roofing, bridges, rigid foam insulation posts & beams, boardwalks, structured insulation panels (SIP) and more. Lag screws feature a round washer head, extra sharp type 17 auger point, deep and sharp spiral and made from hardened steel. Bronze Star Construction Lag Screws are ACQ compatible and are designed to protect against the corrosive qualities of chemically pressure treated lumber such as ACQ, CCA and more. Coated lag screws also exhibit outstanding abrasion resistance. Features include: “5 /16" Bronze Star Construction Lag - 1 carton,” “ACQ compatible coating for pressure treated lumber,” “Round washer head,” “Extra sharp type 17 auger point with deep, sharp spiral,” and “hardened steel”.