Construction lag screws are stronger and more durable than ordinary lag screws. The built-on round washer gives a neat, finished appearance. Triple coating shown over 1200 hours of corrosion resistance in ACQ and salt spray conditions. Compatible with pressure treated lumber & can be used with tannic wood such as Cedar and Redwood. Deep cutting threads allow driving ease. Great for ledger boards, heavy timber construction, insulation panels, pole to post and more! ACQ Compatible Coating, Hardened Steel, Round Washer Head, Extra Sharp Type 17 Auger Point, Deep Sharp Spiral.