Yellow Color Zinc Plated Hex Flange Bolt DIN6921

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

Flange surface design

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.

Hexagonal or twelve pointed head

Commonly designed as a hexagonal head, easy to tighten with standard tools; Some high-strength models use twelve corner heads.

Anti slip tooth pattern

The flange surface of some flange bolts has radial tooth patterns to enhance friction and prevent loosening.

Main advantages

No need for additional gaskets

The integrated flange replaces traditional gaskets, simplifies installation steps, and reduces costs.

Anti vibration and anti loosening measures

The flange surface increases friction, and the tooth pattern design further prevents bolts from loosening in vibration environments.

Uniform force

The flange disperses the load, protects the surface of the connected parts, and avoids crushing or deformation.

Sealing enhancement

When combined with flange surfaces and soft materials such as rubber gaskets, the sealing performance can be improved.

Common application areas

automotive industry 

The key parts such as the engine, gearbox, and wheel hub are adapted to high vibration environments.

Machinery manufacturing

Heavy equipment, machine tools, pumps, valves, and other connections that require high preload force.

Architecture and Steel Structures

Wind and earthquake resistant structures such as bridges, steel frames, curtain walls, etc.

Rail Transit

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)