China Suppliers Factory Yellow Zinc Plated Hex Flange Bolt DIN6921 - Carbon Steel, Stainless Steel, Various Grades
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
QWhat is a flange bolt and how does it work?
A flange bolt is a special bolt featuring an integrated flange surface (circular gasket) below the head. This design increases the contact area, disperses pressure, and reduces damage to the connection surface.
QWhy do flange bolts eliminate the need for traditional gaskets?
Because the flange surface is integrated directly into the bolt head, it functions as a built-in gasket. This simplifies installation steps and reduces the cost of purchasing extra washers.
QHow do flange bolts prevent loosening in high-vibration applications?
Some flange bolts are designed with radial anti-slip tooth patterns on the flange surface. These tooth patterns enhance friction, preventing the bolt from loosening in high-vibration environments like automotive engines.
QWhat head styles are commonly available for flange bolts?
They are commonly designed with a hexagonal head for easy tightening with standard tools. For high-strength applications, twelve-pointed head designs are also used.
QWhat materials and surface treatments are available for flange bolts?
Flange bolts are commonly available in carbon steel (grades 4.8, 8.8, 10.9), stainless steel (A2-304, A4-316), and alloy steel. Surface treatments include Galvanized, Dacromet, Hot dip galvanizing, and Phosphating depending on the required level of corrosion and wear resistance.
QIn which industries are flange bolts most commonly used?
They are widely used in the automotive industry, machinery manufacturing, architecture and steel structures (like bridges and curtain walls), and rail transit where high safety, reliability, and vibration resistance are required.