Coarse Thread Self-Locking Head Design Hot Dipped Galvanized Finish For Superior Corrosion Resistance Commercial Grade 307A Threaded Length: 6" of Thread Minimum Tensile Strength: 60,000 PSI / Hardness: 69 to 100 HRB Minimum Coating Thickness: 0.0020” (50 microns) Specifications Met/Exceeded: Coating Specifications: ASTM F2329/F2329M or ASTM A153/A153M ; Steel Mechanical Specifications: ASTM A307 Grade A ; Dimensional Specifications: ASME B18.5 RoHS Compliant Kit Includes: 25 Bolts, 25 Nuts and 25 USS Flat Washers Hot-dip galvanized carriage bolts are used for heavy-duty, corrosion-prone applications, especially those involving wood and metal. Their primary use is in construction, infrastructure, and outdoor projects like fencing, decks, and playground equipment because the hot-dip galvanizing process provides a thick zinc coating that protects against rust and corrosion. The smooth, rounded head and square neck underneath prevent the bolt from spinning when the nut is tightened, making them ideal for wood-to-wood and wood-to-metal connections. Key uses Construction and infrastructure: Used for structural framing, joining wood and metal components, and securing parts on bridges or other large projects. Woodworking: Ideal for assembling wooden structures like decks, fences, docks, and playground equipment, where a smooth finish is desired. Outdoor equipment: Their corrosion resistance makes them suitable for agricultural machinery, gates, and other outdoor equipment that must withstand the elements. Security applications: Can be used in situations where security is a concern, as they can only be tightened from one side. Why choose HDG carriage bolts? Corrosion resistance: The hot-dip galvanizing process creates a thick, protective zinc coating, making them highly resistant to rust and corrosion. Self-locking design: The square neck under the smooth, domed head locks into the material (especially wood), preventing the bolt from spinning when the nut is tightened. Durability: The robust coating and design make them a long-lasting and reliable choice for heavy-duty applications. Aesthetics: The smooth, rounded head provides a finished look and minimizes the risk of snagging.