Coach screws, also known as lag screws, are heavy-duty fasteners commonly used in woodworking and construction. These screws are designed for securing heavy timber to one another or for fastening ironmongery or concrete to timber. They feature a hexagonal head with a threaded barrel that tapers to a sharp, pointed tip. The unique head shape of coach screws allows for increased torque application using a spanner or wrench during installation, providing a secure and stable fastening solution for various applications in carpentry and construction projects.