Coach screws, also known as lag bolts or lag screws, are screws with a Hexagonal or Square Head and a Coarse Thread. The coarse thread of a coach screw provides a strong grip, and the large head distributes the force of the screw over a wider area. The square or hexagonal head also allows for greater torque to be applied during installation, which helps ensure a tight fit.
Coach Screws are often used in conjunction with washers to create a more secure connection, and can be installed using a socket wrench or adjustable wrench. They are commonly used for heavy-duty applications where a strong, secure connection is required, such as in construction and heavy machinery.