China Factory Suppliers Yellow Zinc Plated Hex Flange Bolt DIN6921 – Carbon Steel, Stainless Steel, and More
Flange bolt, also known as flange bolt, is a special type of bolt with a flange surface (flange), widely used in situations that require high preload, anti loosening, and sealing. Here is a detailed introduction:
Structural characteristics
There is an integral flange (circular gasket) below the bolt head, which increases the contact area, disperses pressure, and reduces damage to the connection surface.
Commonly designed as a hexagonal head, easy to tighten with standard tools; Some high-strength models use twelve corner heads.
The flange surface of some flange bolts has radial tooth patterns to enhance friction and prevent loosening.
Main advantages
The integrated flange replaces traditional gaskets, simplifies installation steps, and reduces costs.
The flange surface increases friction, and the tooth pattern design further prevents bolts from loosening in vibration environments.
The flange disperses the load, protects the surface of the connected parts, and avoids crushing or deformation.
When combined with flange surfaces and soft materials such as rubber gaskets, the sealing performance can be improved.
Common application areas
The key parts such as the engine, gearbox, and wheel hub are adapted to high vibration environments.
Heavy equipment, machine tools, pumps, valves, and other connections that require high preload force.
Wind and earthquake resistant structures such as bridges, steel frames, curtain walls, etc.
Scenarios with high requirements for safety and reliability, such as rail vehicles and signal equipment.
Material and surface treatment
Common materials
- Carbon steel (such as 4.8 grade, 8.8 grade, 10.9 grade)
- Stainless steel (A2-304, A4-316, corrosion-resistant)
- Alloy steel (high-strength or high-temperature resistant)
Surface Treatment
- Galvanized (conventional anti-corrosion)
- Dacromet (high corrosion resistance)
- Hot dip galvanizing (heavy-duty anti-corrosion, suitable for outdoor use)
- Phosphating (enhancing wear resistance)
Frequently Asked Questions
Q1: What is a flange bolt?
A flange bolt is a specialized fastener featuring a circular ridge (flange) under the head. This integrated flange acts as a built-in washer to distribute load and prevent damage to the mating material.
Q2: Do flange bolts require separate washers?
No, flange bolts are designed to eliminate the need for separate washers, simplifying installation, reducing assembly time, and lowering overall component costs.
Q3: What is the purpose of the serrations on some flange bolts?
The serrated or tooth-patterned flange surface increases friction against the mating surface, providing excellent anti-vibration and anti-loosening properties.
Q4: Where are flange bolts commonly applied?
They are widely used in high-vibration and high-load environments, such as the automotive industry, heavy machinery manufacturing, steel structures, and rail transit systems.
Q5: What materials and surface treatments are available for flange bolts?
They are typically manufactured from carbon steel, stainless steel, and alloy steel. Common surface treatments include galvanization, Dacromet coating, hot-dip galvanizing, and phosphating for enhanced wear and corrosion resistance.
