The lag bolt is a heavy-duty fastener that can hold up to serious stresses. They have thick shafts, coarse threads and large heads that allow them to grip materials tightly when driven in with a wrench or hex screwdriver. They can be used in wood-to-wood connections, lag shields, deck construction and other projects that require durable fasteners.
A common misconception is that hex bolts are the same as lag screws. While they do both feature hex-shaped heads, they are two distinct types of fasteners with unique characteristics and applications. Read on to learn more about the differences between lag bolts and lag screws and which one is right for your project.
Lag Screws
A hex lag screw is simply a larger version of an ordinary wood screw. They have the same sharp, cutting threads as wood screws but are scaled up in size for heavy-duty uses such as holding down drywall. They are not self-tapping, however, and require a pre-drilled hole for proper installation.
A typical hex lag screw is 6 inches long and has coarse threads that are similar to those of a regular wood screw or sheet-metal screw. They also have a shoulder below the head (in longer lengths) that helps with added strength and durability. They are available in a variety of materials to suit the needs of different environments and applications, including silicon bronze for corrosive and marine conditions, 304 stainless steel for standard use, and grade 316 for high corrosion resistance in harsh environment applications. lag bolt