Gaskets and washers
Gaskets are mechanical seals which fill the space between two or more mating surfaces. They are generally used to prevent leakage from, or into the joined objects while under compression.
A gasket allows “less than perfect” mating surfaces on machine parts where they can fill irregularities. Gaskets are commonly produced by press cutting from sheet materials. However, should your application require a non standard or bespoke thickness; UK Seals can offer fully moulded gaskets at competitive prices.
Traditionally Asbestos was a common gasket material for applications such as high pressure steam systems. Due to the health hazards associated with it, compressed non asbestos fibres (CNAF) are now used in its place.
Ideally a gasket should be made from a material that is to some degree yielding, such that it is able to deform and tightly fill the space it is designed for. This includes any slight irregularities. Some joints may also require an application of sealant directly to the gasket surface to function properly.
A washer is a thin plate (typically disk-shaped) with a hole that is normally used to distribute the load of a threaded fastener such as a screw or nut. Other uses are as a spacer, spring, wear pad, preload indicating device, locking device, and to reduce vibration.
Washers are usually metal or plastic. Rubber or fibre gaskets used to stop the flow of water are sometimes referred to colloquially as washers. However, while they may look similar, washers and gaskets are usually designed for different functions. They are made differently and are very reasonably priced considering their technical merits.