1 & ASTM A307A The hex head allows for lag screws to be tightened with more torque than can be used on phillips head screws, though a pilot hole is still required prior to installation. They are ideal for use on decks since installation can be accomplished without having access to both ends of the fastener, as opposed to standard hex bolts that require a nut on the opposite end.
.Lag bolts are designed for securely fastening heavy timbers to one another, or to fasten wood to masonry or concrete. A lag screw is similar to a wood screw, but generally is much larger with a hexagonal head.
A lag screw is similar to a wood screw, but generally is much larger with a hexagonal head..Lag bolts are designed for securely fastening heavy timbers to one another, or to fasten wood to masonry or concrete.