A hex lag screw (or lag bolt) is a heavy-duty fastener used to connect lumber or other materials that can bear intense load. It’s different from other types of screws like wood screws, sheet metal screws and self-drilling screws because it’s larger, has coarse threading and needs to be driven into a pre-drilled hole.
Unlike other screws, which come with various head styles (like slotted heads or Philips heads), hex lag screws only have a hex head for driving into a wrench or hex driver. The hex head helps the screw to be tightened or unscrewed using high torque. Lag screws are available in a variety of materials, including carbon steel, galvanized or stainless. The latter is ideal for outdoor or marine applications, as it offers superior corrosion resistance.
Lag screws also differ from other screw types because they have a coarse threading, which is better suited for holding materials together than finer threads are. They also feature a gimlet point, which is shaped to dig into wood. The gimlet point prevents the screw from coming loose over time.
Portland Bolt offers hex lag screws in several diameters and lengths, all meeting ASME, AASHTO and other specifications. The company can also produce nonstandard head dimensions and custom thread sizes. For example, it can provide a hex lag screw with a Phillips head recess for use in electrical projects. Moreover, it can offer a hex lag screw with an internal-drilling tip, which cuts the holes as the screw is installed, eliminating the need for a pre-drilled pilot hole. hex lag screws