
2026-06-05
A flange bolt is a type of hex bolt featuring an integrated washer-like flange beneath the head. This built-in flange distributes clamping load over a larger surface area, reducing the need for a separate flat washer and improving joint reliability. Available in grades 4.8, 8.8, 10.9, and stainless steel, flange bolts — also called flange hex bolts or flange screws — are widely specified wherever vibration resistance and secure fastening are critical.
Flange bolts are trusted across a broad range of sectors. Below are the most common industrial and commercial applications:
The automotive industry is one of the largest consumers of flange bolts. From engine mounts and exhaust systems to suspension assemblies and chassis brackets, flange hex bolts provide vibration-resistant clamping that keeps critical components securely in place. High-strength Grade 10.9 flange bolts and flange nuts are standard hardware on commercial trucks, buses, and off-road equipment.
Structural engineers specify heavy-duty bolts, nuts, and flat washers when connecting steel beams, column base plates, and prefabricated frames. Flange bolts eliminate the need for individual washers, speeding up on-site assembly and reducing hardware inventory. Hot-dip galvanized or zinc-plated flange bolts are preferred for outdoor steel structures exposed to moisture and weathering.
In oil, gas, and water pipeline systems, stud bolts paired with hex nuts are the standard choice for securing pipe flanges. Flange bolts made from stainless steel (A2-70 / A4-80) or alloy steel with anti-rust coatings ensure leak-proof, pressure-resistant joints. Proper torque specification of these fasteners is critical to pipeline integrity.
Manufacturing equipment, pumps, compressors, and conveyor systems all rely on machine screws, hex cap screws, and flange bolts to maintain alignment under constant vibration and thermal cycling. The self-retaining design of a flange bolt minimizes loosening without the need for lock washers, making maintenance more straightforward.
Wind tower foundation connections demand extremely high-strength fastener systems. Large-diameter stud bolts (M36–M72) with structural nuts and hardened washers are used to anchor turbine towers. Corrosion protection — achieved via hot-dip galvanizing or GEOMET® coating — is mandatory for long service life in coastal and offshore environments.
Rail track fastenings, bridge decking, and marine dock structures require corrosion-resistant bolts and screws that withstand salt spray, humidity, and dynamic loads. Stainless steel flange bolts and duplex stainless fasteners are the go-to solution in these harsh environments.
Looking for reliable flange bolts, stud bolts, hex bolts, or custom fastener solutions for your next project? Contact FUJINRUI Fasteners for competitive pricing, fast lead times, and export-ready packaging. We supply anti-rust bolts and screws to customers worldwide