Washers at Wentins

Released On 24th Jun 2024

This guide will hopefully give you a thorough understanding of why we use washers, what we're using them for and which ones to use where. We will be looking at the different varieties and thicknesses as well as material and application, so you have all the information needed before you buy your washers.

Choosing the right washer

You will need to know what the internal diameter of the washer will be, this is crucial to having succesful application. If the washer is the wrong diameter for your application it won't be the end of the world, but it won't create the load share and protection that it should. Following that, you will then need to know what external diameter you want as well as thickness, and this will depend on what the application is. Lastly, it is important to consider what material you need the washer to be. Stainless A2 will be ideal for outdoor applications, Stainless A4 for underwater and heavily weathered areas, Bright Zinc Plated (BZP) for indoor applications and Galvanised for reduced corrosion. 

Form A

Possibly one of the most commonly used washers. Form A washers are pretty standard, mostly used for clamping and/or spacing applications. Available in Zinc, Galvanised, A2 Stainless and A4 Stainless. See our Form A washers here>

Form B

Form B washers are near identical to form A washers, the difference being that form b washers are thinner than form a washers while having the same diameter. These are usually used for the same applications, allowing spacing and clamping but also to prevent loosening. Available in Zinc, A2 Stainless and A4 Stainless. See our Form B washers here>

Form C

These washers have a wider outside diameter allowing for an increased clamping/contact area. These washers are good for heavy duty applications as the load will be spread over larger areas. Available in Zinc, A2 Stainless and A4 Stainless. See our From C washers here>

Form G

Form G washers are the strongest heavy duty washer available. These washers are bigger, both in diameter and thickness, than form a, b and c washers. They are popular for use with timber and plastic as the thick material allows a wider load spread. Available in Galvanised, Zinc, and Stainless Steel.

Repair Washers

Repair washers, also known as penny washers, are a wider outside diameter to spread the load effectively. Each internal diameter can come with multiple outer diameters, M8 x 20, M8 x 25, M8 x 30 for example. These prevent loosening over time as well as protecting the material of the parts involved. Available in Zinc, A2 Stainless and A4 Stainless. See our Repair washers here>

Square Washers

Square washers are just that, washers but in a square shape. These are more often used in timber constructions in conjunction with cup squares. They are typically thick and the wide diameter allows for better load distribution. Available in Zinc, A2 Stainless, A4 Stainless and Galvanised. See our Square washers here>

Spring Washers

These washers are designed to provide a spring like effect when compressed, the spiral type shape is used for tension and pre-load in joint assemblies. They can come as a square section spring or rectangular section spring which refers to the split end section, with the only difference being that rectangular spring washers are more commonly used in more demanding situations. These are also available in Zinc, A2 Stainless, A4 Stainless and Galvanised. See our spring washers here>

Shakeproof Washers

Acting as an anti-vibration washer, shakeproof washer can come as both internal and external. The teeth on the internal diameter will lock onto the bolt when in use, and external washers will lock onto either side, both creating friction and keeps everything from coming loose. These can come in Zinc, A2 Stainless, A4 Stainless. See our shakeproof washers here>

Wavy Crinkle Washers

These are an anti-vibration locking washer used to prevent loosening. They are designed to provide multiple points of contact for increased stability. Our Wavy Crinkle Washers are available in A2 Stainless. See our wavy crinkle washers>

Other types of washers...

Starlock Capped Washer: A push on fastener that once they have been put on, they are near impossible to remove without damaging the washer. Often used on axels to prevent them from coming loose. See our Starlock Capped Washers here>

Fibre Washers: Suitable for general spacing like a standard washer, but designed to be used in and around liquids as they are absorbant and expand when in contact with liquid. This way, they fill the space and provide a water tight seal. See our fibre washers here>

Neoprene Washers: Often used in plumbing applications as the flexible material allows enough compression to allow a tight seal. This material is also corrosion resistant. See our Neoprene washers here>

Nylon Washer: These are non corrosive washers and therefore, are ideal for outdoors or potentially moist areas as they are resistant to rusting. See our Nylon washers here>

Copper Washers: Useful in construction and industrial machinery as well as plumbing applications. The malleable material allows them to seal in high pressure systems. See our copper washers here>

Shim Washers: Thin washers, designed for precise spacing. Whereas a standard washer would be used for spreading the load and protecting the components, these would be used more for spacing and leveling. See our shim washers here>

Wedge Lock Washer: Generally used in places where they would need to be immune to small vibrations over time. Similar to most washers, they are beneficial in keeping the movements minimal and preventing bolts from loosening. See our Wedge Lock Washers here>

Choosing the right material

Bright Zinc Plated (BZP): Bright Zinc plating is effectively a layer of zinc which prevents moisture from reaching the underlying material. Primarily used to prevent corrosion. Generally BZP is fine to use in most situations, you would only want to avoid areas that have a salty atmosphere or if it will be in constant contact with water. 

A2 Stainless Steel: Non-magnetic stainless steel, also referred to as 304 stainless. This material is suitable for general use, but often favoured for areas requiring stronger corrosion resistance than BZP. Put simply, A2 stainless will not rust, as long as it's not in contact with salt.

A4 Stainless Steel: Similar to A2 stainless steel, this material is still suitable for general use, however, you would use A4 for extremely corrosive applications such as coastal environments. This will also be referred to as 316. In technical terms, A4 stainless will have a lower carbon content than A2 Stainless, which makes it a softer metal but more practical in terms of corrosive properties. 

Galvanised: Fixings made from galv can resist most weather and is good in terms of corrosion, it is also cheaper than A2 and A4 stainless. 

Brass: Washers made from brass are durable and often used in plumbing applications as they are resistant to corrosion. It is also a good conductor of electricity and easy to work with in terms of welding and soldering.