A Carriage Bolt is a fastener with a domed, rounded head and a square neck directly beneath it. The square neck prevents the bolt from turning when tightened, allowing for secure fastening without the need for a tool on the bolt head. The smooth, rounded head provides a clean and tamper-resistant appearance. ... Typically made from materials like stainless steel, carbon steel, or galvanized steel for durability and corrosion resistance, carriage bolts are commonly used in woodworking, construction, and outdoor projects like decking and fencing. They are ideal for applications requiring a flush finish and a strong, secure joint.