50 Pack, 5/16" x 5-1/2", Galvanized Hex Lag Screw, Extremely Sturdy, Ideal For Outdoor Projects, Attach Objects To Wood, Common Applications Include Retaining Walls, Deck Frames & Outdoor Play Equipment, When Used With A Lag Shield Can Also BeUsed For Masonry Application, Coarse Threads With A Hexagonal Drive & Requires Clearance Above The Fastener, GalvanizedFinish Which Contains More Corrosion Resistant Properties, Allowing It To Last Longer Than Those Made With Traditional Steel, Use In A Pre-Drilled Hole.