The Cup Square Bolts (also known as Mushroom Head, Carriage or Coach Bolts) are for general purpose use. These bolts have a Zinc plated finish and are made from carbon steel. These bolts have a smooth, round head with no external drive for appearance, safety and security. The square shank under the head pulls into the material as the nut is tightened and prevents the bolt from turning once completely installed. Common applications for this bolt include fence construction and outdoor furniture. They are generally pushed into a pre-drilled hole and then tightened in place with hex nuts and flat or lock washers.
4.6 grade steel
Zinc plated finish