Heavy hex bolts, distinguished by their thicker heads, are commonly made from high-grade steel, including low and medium carbon steel, alloy steel, and stainless steel, to provide increased strength and durability for high-strength structural applications. These are industrial-grade fasteners characterized by a larger and thicker hexagonal head and shank compared to standard hex bolts. They are designed for use in heavy-duty applications where high strength and load-bearing capability are required, such as structural steel connections, bridges, heavy machinery, and high-pressure pipelines.
Applications:
Heavy hex bolts are typically used in:
- Structural steel fabrication
- Bridges and buildings
- Wind turbine towers
- Heavy machinery and equipment
- High-temperature or high-pressure piping (especially in flange connections)
- Oil & gas and petrochemical industries
Advantages:
- High Load Capacity: Suited for high-tensile strength applications.
- Improved Torque Transfer: Larger head provides more surface contact and better torque distribution.
- Greater Bearing Surface: Reduces the risk of pull-through and enhances clamping force.
- Compatibility with Heavy Hex Nuts: Used with matching heavy hex nuts for optimal performance.
Installation Considerations:
- Torque Requirements: Must follow torque specs based on bolt grade, size, and lubrication.
- Washer Use: Often used with hardened washers to distribute load and prevent embedding.
- Wrench Size: Requires larger wrenches or sockets than standard bolts.
- Preload/Inspection: Preload is critical in structural applications—bolts may be tensioned using turn-of-nut, torque method, or tension-control bolts.
