Lag Screw, 1/2 in, 16 in, Steel, Zinc Plated Hex Hex Drive, 25 PK, Midwest Fastener, Mfr#: 09728

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.