Washers are a thin ring of material with a hole in the centre. They are an essential part of any fastener assembly and are used in conjunction with screws, nuts and bolts. Washers provide a range of benefits, such as preventing wear, reducing pressure, reducing vibration or to prevent the screw from loosening.

Types of Washer

Plain/Flat washers
Lock washers
Bonded washers
Cup washers
Mudguard washers
Shoulder washers
Spring washers
Tap washers

How to choose a washer:

It is important that your washer is compatible with your fasteners and your chosen application. You should consider the following information when choosing a washer.

Size - It is important to ensure that your washer is compatible with other fasteners you are using. The screw or bolt is usually measured in metric dimensions, such as M10 (10mm) or M8 (8mm).
Material - Washers are primarily made from stainless steel or brass. Stainless steel washers are popular due to its durability and corrosion resistance. However, other materials are available, such as ceramic. Washers come in a variety of finishes too, such as chrome and nickel plated.
Shape - The majority of washers are round to match the round head of a screw of bolt. You can also buy square washers for use with bolts with a square head.
Thickness - there is a range of thicknesses available. Thicker washers can provide extra strength.