What are coach screws ?
A screw designed for heavy-duty projects like joining huge lumber or metal are called coach screws. Construction workers and engineers usually call it lag screws or lag bolts and usually come with hexagonal heads used with spanner, wrench or pliers. Coach screws come in wide varieties of sizes, from the very little ones packed with furniture designed to be constructed by the consumer to enormously big ones used in large-scale construction projects.
Coach screws have cylindrical shaft threaded externally that tapers to a point, through a head and the other point. When driving a coach screw into a timber, the thread bites the wood and the head stops the screw from going all the way through the other side of the wood due to the compression given. The coach screw design have been in existence for over 2000 years, although metal screws for woodworking and constructions have only been in play since it became possible to mass-produce them in the late 19th century. The standard size of the coach screws have been manufactured in the time of World War II.
Coach screws are often used in important construction parts due to its strong design, providing the structure’s sturdiness. Generally, screws are more considered in construction rather than nails, because they are capable of easy removal for repeated usage and nails tend to loosen overtime without warning. Coach screws are preferred for joints that see serious use and other areas in which extra support using metal flanges is required.
Ut is important to know the precise size of wrench or spanner used in installing coach screws to prevent the heads from being damaged, making it hard to tighten or loosen. When checking the size of a spanner or wrench, the user should take measurements along both flat ends and from point to point. When using coach screws on wood-to-wood connections or in other applications where the screw will go through wood first, it is best to use washer to avoid the head of the screw from sinking into the wood when tightened.
