What Are Belleville Washers?

What is a Belleville Washer?

These cupped spring washers flatten out as pressure is applied to them. They are commonly used to produce exceptionally high loads in small areas. Coned disk washers can absorb and dampen shocks and vibration as well, making them useful in many industries and applications.

The Many Industry Terms of Belleville Washers

Belleville	Coned – Disc
Conical	Cupped Spring
Spring Lock	Spring
Conical Spring	Disc Spring
Belleville Spring

How Conical Washers Work

The conical spring washer has a cone shape that presses against the underside of the bolt head and into the installation material. This increased tension has a number of benefits including:

Vibration Control (Lock Washer)
Pre-Load
Increased Load
Increased Deflection
Spacing
Dampen/Absorb Shocks

Relevant Definitions

Pre-Load: Refers to the axial load placed on a fastener. Pre-load is considered to be 75% of the proof-load.
Proof-load: A test load a fastener MUST be able to hold without causing any compromise in its integrity. Considered the maximum safe load of a fastener.
Deflection: The degree to which a structural element is displaced under a load.

Due to their resistance to vibrations, conical washers are also considered to be lock washers as they perform a similar function. These disc spring washers are not only useful on their own but can be stacked in several different structures for increased resistance / absorption as well.

Belleville Spring Washer Stacks

Spring washers can be stacked in several structures to increase certain characteristics they produce for optimal performance.

Series Stack

A series stack involves placing the washers top to bottom so that they create a gap in the middle. This can greatly increase the deflection of the stack by adding a spring like effect to the washers. *Note: This stack does not increase the load capacity of the fastener assembly.

Parallel Stack

A parallel stack involves placing all of the washers in the same direction. Each added washer increases the load capacity of the stack. *Note: The deflection does not increase based on this stack.

Parallel/Series Stack

The mixed parallel/series stack involves performing both types of stacks in a single fastener assembly. This increases both the load and deflection and can be arranged to suit almost any situation as needed to comply with the project needs.

Please note that while Belleville spring lock washers are exceptionally versatile and can be stacked in multiple configurations, the washer that rests against the installation material must always have it’s widest portion against the material.

Belleville Washer Uses

Due to Belleville washers being so versatile, they have many different uses and can be found in many different industries.

Spring Washer Uses

Locking (Prevent Fasteners Vibrating Loose)	Limit effects of Relaxation
Spring	Resolve Thermal Expansion
Spacer	Dampen/Absorb Shock
Deter Bolt Yield	Extra Tension
Shim

Industries That Use Conical Washers

Energy	Utility Transmission
Distribution	Pump and Valve Manufacturing
Chemical	Automotive
Transportation	Industrial Automation
And Many More

Can Belleville Washers Be Reused?

Yes, Belleville conical washers can be reused, repeatedly, as long as they are not damaged. Overloading and over-torquing these washers can wear them out over time. As long as they are used properly and checked before reuse, these fasteners can be used again and again to complete projects.

Belleville Washer Installation

Installing Belleville washers is very easy. There are only a few steps to consider:

Determine the project load capacity and deflection.
Decide which Spring Washer Stack will give you the optimal results.
Slide the washers onto a bolt in the optimal stack.
Slide the bolt through the installation material with the stack pressing against the installation material (remember the base washer must be facing down).
Tighten the bolt against the other side of the installation material.

Lock Nuts and Lock Washers

Locking Fasteners

Locking fasteners come in many varieties and styles to help keep your fastener assemblies secure and resist loosen from vibration. Locking nuts and washers are great tools to keep assemblies from accidental loosening, basically they stop things from falling apart! But what kind of locking nut or washer should you buy? Below we explain some of the popular types to help you choose.

Lock Washers

Lock washers are washers with designed changes to add extra friction or tension to your fastener assembly to prevent loosening. Each lock washer is engineered to work for different applications, if you are unsure if the hardware you are selecting is appropriate, make sure to consult an engineer.

Click the name of any type of lock washer or nut you would like to know more about or buy directly from our website.

Lock Washer Type	Description	Image
External Tooth “External Star”	External tooth lock washers are serrated and create tension between the teeth and the installation surface. This increased tension can make it harder for a fastener assembly to vibrate loose.
Internal Tooth “Internal Star”	Internal tooth lock washers have bent teeth that are designed to create tension and friction on the inside of a bolt head or against the nut. They are often chosen over external tooth lock washers due to their cleaner finish.
High Collar Split Ring	High collar lock washers are similar to regular split ring washers except they are made to fit under the head of a socket cap screw. They have a smaller outer diameter designed to fit into a counter-bored hole.
Split Ring	Split ring lock washers are washers with a cut in them and bent into a helicoil shape. As the nut loosens, extra pressure is applied from the expanding lock washer which can stop a bolt from loosening unintentionally

Lock Nuts

Lock nuts are nuts that have been altered in some way to deter them from vibrating loose. Below are a few of the more common types of lock nuts you are likely to come across.

Lock Nut Type	Description	Image
Castle	Castle nuts, while not technically lock nuts, can function as lock nuts after installation. They require that a cotter pin be placed through a hole in a bolt and through the crown of the nut. We consider these to be lock nuts because the cotter pin will hold the nut in place if it comes loose.
Flange Serrated	Flange serrated nuts have one wide side that acts as an integrated washer. The washer side has serrations which, when tightened, can help prevent loosening by adding extra friction to the assembly.
Keps-K	Keps K lock nuts Have an attached spinning washer with teeth that can dig into the assembly. They are similar to that of an external tooth lock washer combined with a nut.
Nylon Insert	Nylon insert lock nuts are a taller nut with the same nylon insert. Threads cut into the insert as installed resulting in a better grip to help prevent a fastener assembly vibrate loose.
Nylon Jam “Thin”	Nylon Jam lock nuts are a low profile nut that have an internal nylon insert. As the bolt is screwed on the threads cut into the nylon holding them in place and preventing vibrations from loosening them.
“Stover” Cone Prevailing Torque	Stover lock nuts have chamfered corners. The distortion in the top threads from the shape of the bolt create resistance to loosening. This is a better choice for high heat applications because no nylon insert is used.
Two Way Reversible	Two way reversible lock nuts have indents on the outside flats of the nut causing distortions of the internal threading. These distortions create resistance of the mating part.

NOTE: We also offer thread locker solutions that can provide a low, medium or high level grip to prevent assemblies from loosening as well.

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Tag: lock washers