Using Flat Washers with Belleville Washers

Standard joint with flat washers (blue) 
& Belleville washers (green)

HEGONG SPRING contains other products and information you need, so please check it out.

it is important to note that a Belleville washer is not a replacement for a flat washer.

Let's start by going over the basic functions of both fastener elements:

• A Belleville washer functions as a spring, adding elasticity under load. This elasticity acts similarly to bolt stretch, maintaining preload in the event of relaxation or joint expansion.
• A flat washer is used to spread out force of a bolt or nut onto a larger area of the joint surface. This protects the surfaces of the joint from damage and prevents embedment (i.e. the bolt head digs into joint surface). Functionally, embedment of a bolt or nut decreases the load of the joint and can be a cause of loosening. 

As you can see, the two fastener elements are designed to solve two different problems. 
 

Why they work well together

As they do not serve the same function, a
 

When a Belleville washer does not require a flat washer

Given the right set of circumstances, a Belleville washer will work just fine without a flat washer. It all depends on the joint surface. As stated above, a Belleville washer does not distribute the load nearly as well as a flat washer. If the joint surface is relatively soft or is susceptible to embedment, the washer may dig in. If the surface is uneven or rough, the increase in friction may cause a lower load. However, if the joint surface is hard, even and smooth, a Belleville may be used without a flat washer with minimal change in joint performance.

Selecting the right flat washer

There are three factors to consider when selecting the right flat washer.

1. It is important to make sure that the Belleville, bolt, and flat washer used are of a similar material family. Stainless steel should be used with stainless steel, and zinc-plated carbon with zinc-plated carbon. This will help to prevent the problems caused by galvanic corrosion and differential thermal expansion. 

2. It is important that the flat washer OD is large enough to accommodate the Belleville's OD. If the washer OD is too small so that the Belleville overhangs, then the loading characteristics will be altered, limiting the defleciton available for

3. The thickness of the flat washer should be at least one-third the thickness of the Belleville washer. This will ensure that the washer itself does not deform under the intended load. This assumes that the flat washer is fully supported by the joint. If the flat washer is not fully supported, then a thicker washer may be warranted. 

If your application requires both load distribution and the spring action of a Belleville washer, using them together can be effective. Always consider the specific requirements of your assembly to determine if this combination is suitable. 

Solon Belleville Springs & washers advantages

Installing 
 
Solon Manufacturing, an industry leader on engineered solutions for critical applications, can help from design through aftermarket to ensure bolts have the correct mating parts that will effectively support any applications. Often there are standard options already available, though a custom Belleville washer can be engineered around specifications.

Solon Belleville Springs & Washers are used in a variety of 

Additional information such as videos,

Learn more about the use of Belleville springs & washers in bolting applications:

Application:
Application:
Calculator:
Calculator:
White Paper:
Video:
Product Selection Tools:

Contact Us

A question we often receive is; should I use a flat washer with a Belleville washer? While there are situations when you can use a flat washer with a Belleville washer, Let's start by going over the basic functions of both fastener elements:As you can see, the two fastener elements are designed to solve two different problems.As they do not serve the same function, a Belleville washer and a flat washer can work in tandem to improve the joint. A Belleville works best when it has a flat and smooth bearing surface. This is because the contact surface, (the top inside corner and the bottom outside corner), slides/rolls as the washer deforms to flat. The less friction created by this motion, the better. Without a flat washer, the bottom bearing surface is up against the joint surface. The addition of the flat washer provides a better bearing surface, as well as distributing the load. A flat washer is not required on top of the Belleville as the bolt or nut usually provide an adequate bearing surface to limit friction.Given the right set of circumstances, a Belleville washer will work just fine without a flat washer. It all depends on the joint surface. As stated above, a Belleville washer does not distribute the load nearly as well as a flat washer. If the joint surface is relatively soft or is susceptible to embedment, the washer may dig in. If the surface is uneven or rough, the increase in friction may cause a lower load. However, if the joint surface is hard, even and smooth, a Belleville may be used without a flat washer with minimal change in joint performance.There are three factors to consider when selecting the right flat washer.1. It is important to make sure that the Belleville, bolt, and flat washer used are of a similar material family. Stainless steel should be used with stainless steel, and zinc-plated carbon with zinc-plated carbon. This will help to prevent the problems caused by galvanic corrosion and differential thermal expansion.2. It is important that the flat washer OD is large enough to accommodate the Belleville's OD. If the washer OD is too small so that the Belleville overhangs, then the loading characteristics will be altered, limiting the defleciton available for preload retention 3. The thickness of the flat washer should be at least one-third the thickness of the Belleville washer. This will ensure that the washer itself does not deform under the intended load. This assumes that the flat washer is fully supported by the joint. If the flat washer is not fully supported, then a thicker washer may be warranted.If your application requires both load distribution and the spring action of a Belleville washer, using them together can be effective. Always consider the specific requirements of your assembly to determine if this combination is suitable.Installing Solon Belleville Springs & Washers to the fastening system ensures a proven and reliable connection. Solon Belleville Springs & Washers increase the elasticity of the bolting system by maintaining consistent, and sufficient bolt preload&#; providing improved bolted joint reliability, preventing unplanned or costly downtime, and protecting your assets.Solon Manufacturing, an industry leader on engineered solutions for critical applications, can help from design through aftermarket to ensure bolts have the correct mating parts that will effectively support any applications. Often there are standard options already available, though a custom Belleville washer can be engineered around specifications.Solon Belleville Springs & Washers are used in a variety of applications and industries to maintain bolt preload on bolted joints and connections. Solon Belleville Springs & Washers minimize the effects of differential thermal expansion, vibration, embedment relaxation, bolt yield/creep, and thermal cycling.Additional information such as calculator tools case studies and technical white papers can be found in our resource library Application: General Purpose Bolting Application: Commercial Bolting Applications Calculator: Bolt Stretch Calculator Calculator: Infinite Bolt Life Fatigue Calculator White Paper: Why Increased Elasticity Leads to Reduced Self-Loosening Video: Solon Belleville Spring Washers Product Selection Tools: Application Specific Calculators

Some people who may need to use compression spring applications that require high load may not be able to distinguish which kind of washers that would best suit for their needs. However, one of the most commonly recommended items for this purpose is the Belleville washer.

What is a Belleville washer?

The Belleville washer is a conical-shaped metal disk designed to support high loads with small deflections compared to conventional helical springs. This washer is often used to reduce vibration, thermal expansion, relaxation and bolt problems. What makes the Belleville washer stand out from other kinds of washers is that it can meet all locking device requirements that other types of washers could not provide.

The main advantage of using a Belleville washer is that once the clamping pressure is applied, it equally distributes the load instead of just concentrating on one part of the washer.

Uses of Belleville Washers

The Belleville washer has been widely known because of properties that make it stand out among others. These include the following:

•          The characteristic curve of a Belleville washer makes it possible to be used in various combinations with the necessary support that an application needs.
•          Other washers have limitations when carrying a load, unlike the Belleville washers that can support large loads even with small insulation space.
•          Because of its annular shape, it is able to force transmission in the center thus being able to equally distribute the load.

The characteristics of the Belleville washer make it useful in landmines. Once the spring has been stepped on by a person or a vehicle, the pressure exerted causes the trigger to flip the adjacent firing pin that is connected to a detonator.

Are you interested in learning more about belleville springs? Contact us today to secure an expert consultation!

This washer is used as a locking device but only in applications that require low dynamic loads such as down-tube shifters in bicycles.

It is also used as an indicator of swelling or shrinkage of wooden propellers in aircrafts. Automobiles also use this kind of disc spring to reduce vibration and noise.

These washers have also been used in the construction of buildings wherein stacks of disc springs are used under buildings as vibration dampers for earthquakes.

Belleville Disc Springs

DIN Belleville springs are conical disc springs with elastic properties. These springs are manufactured according to the specifications of DIN standards, which recommend thickness of more than 6 mm supporting surface.

Springs that follow this manufacturing standard have the ability to accommodate high spring load that traditional helix springs could not provide.

Factors In Choosing the Right Kind of Belleville Washer

Belleville washers come in different designs and sizes. Each of them serves a specific requirement. To help you choose the right kind of Belleville washer, you need to consider the following factors:

•          Torque: This refers to the amount of force that you place on the bolt to flatten the washer to its optimum shape to be able to secure clamping.
•          Diameter: The correct diameter of the washer to be used in the application should be carefully chosen to be able to provide the needed support that your system needs. 
•          Finish: You must be able to determine the kind of environment that the washer may be exposed to so you can eliminate the possibility of breaking the washer due to unfavorable conditions.

Final Word

We hope this guide can help you decide whether a Belleville washer is useful for your intended purpose. If you decide to go for Belleville washers, make sure to take care of them just like you would the entire machine or system.

For more information, please visit belleville springs in series.