The Hillman Group 3664 3/8 By 1-1/2-Inch Lag Screw Stainless Steel, 5-Pack

Lag Screws are used to fasten wood-to-wood and metal-to-wood, attach objects to wood, and affix items to concrete and masonry when combined with lag expansion shields. They are heavy-duty wood screws that are available in larger sizes-both in terms of diameter and length-and usually have a hex head to facilitate higher installation torque using a wrench. While lateral strength is lower than a comparable bolt and nut, lag screws are useful when access to one side of the joint is limited, the appearance of a nut is undesirable or through-bolt length is excessive.