High Strength Heavy Hex Bolt is a high-performance fastener designed with an oversized heavy hex head to provide a larger bearing surface and improved load distribution compared with standard hex head bolts. It is commonly used in structural steel and other heavy-duty assemblies where reliable preload, high tensile capacity, and durable corrosion protection are required. Available in multiple standards, grades, materials, and coatings, it supports demanding environments such as offshore, chemical, and outdoor infrastructure.
Product Parameter (Specification)
| Standard | ASTM/ANSI, ASME, DIN, EN, ISO, JIS (e.g., ASTM F3125 (A325/A490), ASME B18.2.1, DIN 6914, EN 14399) | Material | Carbon steel, Alloy steel, Stainless steel (304/316), Aluminum, Brass |
| Surface Treatment | Zinc Plated, Hot Dip Galvanized (HDG), Black Oxide, Geomet, Dacromet, Nickel Plated, Zinc-Nickel Plated, Plain (Oil) | Shank | Full thread / Partial thread (typical for structural use) |
| Grade | 8.8, 10.9, 12.9, ASTM F3125 (A325/A490), A193 B7/B7M, A320 L7, A2, A4, 304, 316 | Size | M6–M72 (customizable) / Inch sizes available upon request |
| Unite | Piece,KGS,TON | Packing | Bulk cartons with pallet; small boxes in cartons with pallet; wooden case export packing (optional) |
Product Application
High Strength Heavy Hex Bolts are widely used in high-load, safety-critical connections, including steel structures, industrial frames, power and energy equipment, mining machinery, and oil & gas installations. The heavy hex head design helps enhance bearing area, while strength grade and coating selection can be matched to project requirements such as preload control, vibration resistance, and corrosion exposure.
High-Strength Hex Bolt Application Scenario Table
| Industry Sector | Specific Scenario | Recommended Class | Core Usage Considerations |
| Steel Construction | Steel beam-column connections, structural frames | EN 14399 / ASTM F3125 (A325) / Class 8.8–10.9 | Use compatible nuts/washers, ensure correct preload method, and maintain traceability. |
| Bridges & Infrastructure | Bridge girders, highway sign structures, towers | ASTM F3125 (A325/A490) + HDG (where allowed) | Prioritize fatigue performance, corrosion protection, and consistent installation control. |
| Oil & Gas | Skids, pipe supports, base assemblies | ASTM A193 B7/B7M / ASTM F3125; coating per environment | Consider temperature range, chemical exposure, and documentation requirements. |
| Wind Power | Tower sections, nacelle frames | Class 10.9 / ASTM F3125 with controlled coating | High vibration/cyclic load: verify torque-tension method and locking strategy. |
| Mining & Heavy Machinery | Crushers, conveyors, heavy equipment frames | Class 10.9–12.9 / Alloy steel options | Shock loads: focus on strength, thread fit, and coating durability. |
| Marine & Coastal | Port equipment, coastal steelwork | Stainless A4 (316) / suitable protective systems | Salt corrosion resistance: confirm coating/material compatibility. |
| Power Generation | Turbine auxiliaries, structural supports | A193 B7 (high temp) / A320 L7 (low temp) | Confirm operating temperature, toughness needs, and required certificates. |
How to Order / Quick Specs Checklist for Inquiry
To help our technical sales team identify your specific fastener needs quickly, please include the following specifications in your inquiry. Because accurate details allow us to provide a precise B2B quote, we need the following information:
- Standard (e.g., ASTM F3125 / EN 14399 / DIN 6914 / ASME B18.2.1)
- Diameter & Length (e.g., M24×120 or 1″×5″)
- Thread type (Metric/UNC/UNF) + Full thread or Partial thread
- Grade / Property class (e.g., 10.9 / F3125 A325 / A193 B7)
- Material requirement (Carbon/Alloy/Stainless 304/316)
- Surface treatment (HDG / Zinc / Geomet / Dacromet / Plain / Zinc-Nickel)
- Quantity (PCS or weight)
- Matching nuts & washers needed? (Yes/No; specify standard)
- Marking & traceability requirements (Heat number, head marking)
- Inspection & documents (MTC/EN 10204 3.1, dimensional report, coating report)
- Packing requirement (bulk / small box / pallet / export case)
- Delivery destination & Incoterms (EXW/FOB/CIF, etc.)
Ready to secure your cold-weather project? Contact QISHENG today with your specific requirements. Subsequently, our dedicated team will quickly provide you with tailored fastening solutions and highly competitive B2B pricing.
