Lag screws for wood are large, heavy-duty fasteners that are used to secure lumber and other materials in applications where they must withstand high loads. They have a thicker shaft than wood screws and are designed to be driven with more force without stripping the head. They also have a coarser thread that helps them bite into the material more securely. While they are more expensive than wood screws, lag screws are well-suited for heavier applications that require stronger joints under higher stress.
The difference between a lag screw and a wood screw is that a lag screw has a hex head and a gimlet point, while a wood screw has a blunt end. A lag screw is also larger and requires a special drill bit to drive it into place, but can be inserted into holes that are as big as the head of the screw. It is advisable to use a washer when using a lag screw, as this will increase the surface area of the screw that contacts the application material and help prevent damage to the materials.
While they are often referred to as lag bolts, technically a lag screw should be called a screw since it is assembled with a nut and has machine threading. However, the terms are used interchangeably and both are designed to join materials together with heavy load. Lag screws are made from a variety of materials, including stainless steel and zinc alloy, but are most commonly manufactured from hot-dip galvanized metal.
They are most commonly used to fasten pieces of heavy lumber and other materials that must withstand an intense amount of load, such as in construction projects. They can also be used to fasten metal, stone, or concrete to wood. The hex head of the screw allows it to easily grip the surfaces of these different materials.
When choosing a lag screw, it is important to select the right length for your specific application. Lag screws are available in a wide range of lengths, but the most common sizes are 3/8-inch and 5/16-inch. A longer lag screw will be better for securing larger pieces of lumber, while a shorter one is appropriate for smaller tasks.
It is also a good idea to lubricate the head of a lag screw prior to use. This will make it easier to turn, and it will help protect the threads from damage caused by vibration or exposure to corrosive materials. Beeswax, paraffin wax, or bar soap can all be used to lubricate a lag screw. It is important to note that glycerin-based products should not be used, as they will cause the screw to rust more quickly.
While lag screws are usually used to fasten materials in construction, they can also be used to create strong connections for furniture and other home improvement projects. The key to selecting the right lag screw for your project is understanding the differences between it and other types of screws, such as wood screws or nails.