Products
Carriage Bolts, also known as coach bolts or round head square neck bolts, are a fundamental fastening solution characterized by their smooth, domed head and a square section immediately beneath it. At Donghuang, we manufacture high-quality carriage bolts that are essential for wood-to-wood and wood-to-metal applications. The unique square neck is designed to lock into the material (specifically timber) or a pre-cut square hole in metal, preventing the bolt from turning when the nut is tightened. This feature makes them ideal for applications where only one side of the fastener is accessible for tightening.
Our production process at Donghuang utilizes precision cold-heading technology to ensure every carriage bolt meets international standards such as DIN 603 and ANSI/ASME B18.5. We primarily use high-grade carbon steel (Grade 4.8, 8.8) and Stainless Steel (SS304, SS316) to cater to different load-bearing requirements. For outdoor construction, such as decking, fencing, and playground equipment, we recommend our hot-dip galvanized or zinc-plated finishes. These coatings provide a thick protective layer against moisture and oxidation, ensuring the structural longevity of your projects even in harsh coastal or humid environments.
One of the primary advantages of Donghuang carriage bolts is their safety profile. Because the head is smooth and rounded, it cannot be gripped by a wrench or pliers from the outside, providing a significant level of security for public structures like park benches and security gates. The aesthetic finish of our bolts makes them a favorite among architects and furniture designers. Whether you are working on a rustic timber frame or a modern commercial installation, our bolts provide a clean, professional appearance without compromising on clamping force. The square neck is precision-forged to avoid stripping the wood fibers, ensuring a tight fit every time.
Choosing Donghuang means choosing reliability. Our quality control team performs rigorous tensile strength and hardness tests on every batch. We understand that in construction, a single failed bolt can lead to costly delays. That is why our carriage bolts are engineered for maximum durability and ease of installation. We offer a vast range of sizes, from M5 to M20, with various lengths to suit any material thickness. By partnering with Donghuang, you gain access to a supply chain that prioritizes technical excellence and customer satisfaction, ensuring that your fastening needs are met with the highest industry standards.
