Zinc plated. Looking for a strong and heavy-duty fixing when working with timber? These coach screws are tough, reliable and easy to use - with a sharp tip and coarse thread, they're easy to insert for a firm and secure fit, and the traditional hexagon head allows you to achieve even greater torque with a socket driver. They are perfect for fixing to timber in fencing and joinery applications. They are zinc-plated for even greater durability.