Extra Large Hex Fasteners for Steel Building

In steel building construction, securing massive structural members demands fasteners that can withstand extreme tension, shear, and vibration over decades of service. For engineers and fabricators, the choice of connection hardware directly influences frame integrity and long-term safety. Our range of Heavy Duty Hex Head Bolts for Structural Steel is forged from quenched and tempered alloy steel to meet ASTM A325 and A490 specifications, delivering reliable clamping force in beam splices, column bases, and moment-resisting joints. When designing wide-span industrial frames, Large Size Structural Hex Bolts for Steel Frame provide oversized bearing surfaces and deep thread engagement that prevent loosening under cyclic loading. For heavy crane girders, bridges, and high-bay metal buildings, Big Diameter Hex Bolts for Metal Structure Works are available in diameters up to 3 inches with full-body traceability, making them ideal for slip-critical connections where every joint undergoes rigorous inspection. These fasteners are designed to reduce erection time through optimized head geometry that fits standard heavy wrenching equipment, allowing crews to torque assemblies precisely in the field.

Extra Large Hex Fasteners are manufactured to bridge the gap between standard industrial bolts and custom-made high-strengthened connectors. These oversized fasteners are characterized by a heavy hex head profile that provides six flat sides for superior wrenching, exceptional clamp load distribution, and resistance to rounding under high-torque installation. Each batch undergoes magnetic particle or ultrasonic testing, and all products are shipped with full mill test reports. The chemical composition and mechanical properties are tailored to the demanding environment of steel building assembly, where exposed joints face wind, seismic forces, and thermal expansion daily.

Key dimensional and mechanical properties of Extra Large Hex Fasteners are listed below to assist specifiers in verifying component suitability for their steel building projects.

• Across Flats (Wrench Size): 1-1/4" to 4-5/8" depending on thread diameter, ensuring compatibility with heavy-duty impact sockets.
• Head Height: Designed per heavy hex pattern to maintain sufficient grip length without adding unnecessary weight.
• Thread Length: Available in short thread (standard) and full thread variations; standard thread length follows ASME B1.1 formulas for structural bolting.
• Proof Load: Exceeds 85,000 psi for A325 grades and 120,000 psi for A490 grades, tested batch-wise prior to shipment.
• Tensile Strength: 120–150 ksi for quenched and tempered alloy steel, meeting or exceeding SAE J429 Grade 8 requirements.
• Yield Strength: Minimum 92,000 psi (A325) or 115,000 psi (A490), providing adequate deformation resistance during preload application.
• Elongation: 14–18% in 2-inch gauge length, indicating high ductility for energy absorption under extreme loads.
• Hardness: Rockwell C 25–38 depending on grade and diameter; case-hardened options available for wear-prone installations.
• Surface Coatings: Hot-dip galvanized per ASTM A153 for corrosion resistance in outdoor steel buildings; mechanical zinc flake (Geomet) for environmentally friendly protection without hydrogen embrittlement risk.
• Marking: Permanent die-stamped manufacturer ID, grade symbol, and heat number on every bolt head for full traceability.