Can Flange Bolts Replace Washers?

Flange bolts have a wider base under the head, which serves a similar purpose to a flat washer. In many applications, they can be used without an additional washer. However, this does not mean they can replace all types of washers. It depends on the application and the type of washer being used.

Flange Bolts

How Do Flange Bolts Work?

A flange bolt has a built-in flange under the head. Compared with a standard hex bolt, it provides a larger contact area when tightened, helping distribute the load across the joint.

Flange bolts are generally available in two designs:

• Non-serrated flange bolts: Have a smooth surface under the head and are commonly used for general fastening.
• Serrated flange bolts: Have small teeth under the flange that grip the mating surface and help prevent loosening.

The built-in flange means a separate flat washer is often unnecessary.

Flange Bolts

Can Flange Bolts Replace Flat Washers and Lock Washers?

The answer depends on the type of washer. Flange bolts can take the place of some flat washers, but they do not perform every washer function.

• Flat washers: A flange bolt can usually replace a flat washer when the purpose is to provide a wider bearing surface and distribute the load.
• Spring washers: A flange bolt does not provide the spring force of a spring washer, so it cannot directly replace one.
• Lock washers: Serrated flange bolts can help resist loosening, but their locking action is different from that of a separate lock washer.
• Sealing washers: A flange bolt cannot replace a sealing washer when the connection needs to prevent water or oil leakage.

For this reason, it is important to check the original purpose of the washer before switching to a flange bolt.

Flange Bolts or Regular Hex Bolts with Washers?

Both options are widely used, but they suit different assembly requirements.

Flange bolts reduce the number of separate components and are convenient for applications where a built-in bearing surface is enough. They are commonly found in automotive parts, machinery, and metal equipment.

Regular hex bolts with separate washers offer more flexibility. You can choose washers with different materials, thicknesses, and surface treatments to suit the application. They are also a better option when a special washer is required.

The choice comes down to the joint design, contact surface, and fastening requirements.

Flange Bolts

Xinchi Fastener Factory

Established in 2007, Xinchi Fastener Factory has 102 cold heading machines and a daily production capacity of over 10 million pieces. The new factory covers 30,000 square meters and consists of two six-story buildings.

Xinchi Fastener Factory

We manufacture a wide range of fasteners, including flange bolts, flange nuts, DIN 1624 T nuts, Hopper Feed T nuts, rivet nuts, threaded insert nuts, square weld nuts, hex weld nuts, DIN 571 wood screws, bolts, and washers.