What is a Gasket?


gaskets seals

‘What is a gasket?’ This is not the easiest of questions to answer. The reason for this is that people can mean many different things when they talk about a ‘gasket’; they can be used to perform many different functions. On a very general level a gasket might be defined as a flexible component that sits in-between two other surfaces. In this article we’ll take a brief look at some of the problems in answering the question ‘What is a gasket?’ Hopefully, by the end of it, this will give you a better idea of what a gasket is and how they work.

The Problem of Defining a Gasket

Gaskets are commonly made of a flexible material such as rubber, paper, or cork. In fact, there are many different materials that gaskets can be made out of (we stock some 1,200 different grades) so gaskets cannot simply be defined by means of the material that they are made out of. Gasket materials are, however, typically flexible as they are usually compressed between two other surfaces. Having said this, it is also possible to find gaskets made of metal: such as spiral wound or copper head gaskets.

A similar problem arises when we try and define a gasket by its function. Gaskets can be used for many different purposes, such as: sound and noise reduction, anti-vibration, packaging, hygiene, sealing, and as supports/mountings. For these reasons, gaskets are found in many different products, in many different industries. For instance, gaskets can be found inside of: cars, planes, boats, trains, pumps, and electrical equipment (from electronic tills and hi-fi equipment to lighting and industrial electrical transformers). Gaskets find application in industries as diverse as food processing, petrochemical, oil and gas, pharmaceutical, and water.

The properties of a gasket are typically those of the material out of which it is manufactured. For this reason, gasket materials are selected for their characteristics: such as their resistance to chemicals, acids, alkaline, extreme temperatures, and pressures, and their ability to withstand different environments (such as deep-sea, mining, and even in space). Similarly, the specification of a gasket is defined by its operating environment.

Gaskets for Sealing Purposes

oil and gas gaskets

Perhaps the most common use of a gasket is as a component of a sealing system, in which one of the major functions of the gasket is to create a seal between two other surfaces. (For instance, pipe gaskets are used to create a seal between two pieces of pipe when laying a pipeline). The exact function of a gasket in this respect is to prevent the escape or ingress of fluids (liquids or gases) even at extreme pressure and temperature. Yet the function of a gasket is not only to provide a seal to prevent liquids or gases from escaping, but it is also an important safety device. In this respect it is important for the gasket to be the weakest component of the sealing system so that it fails in response to a problem.

The consequences of a gasket not failing in response to a problem are far greater than simple gasket failure. If the gasket does not fail in response to a build-in pressure then the consequence is the potential bursting of the pipe and/or explosion.

It is also important that the gasket allows for essential maintenance, by allowing the sealing surfaces to be separated and reassembled. For this reason, it is important for the gasket to remain in good condition for as long as possible. The life of a gasket can be significantly improved by selecting the right material for the application, and by taking into account all of the features of the environment in which it will be used.


As we have seen, it’s not easy to define what a gasket is: as they can be made out of many different materials, perform many different functions, and be used in many different industries. Having said this, the most common use of a gasket is to interface between two surfaces to improve the function of the components.

If you have any technical questions then please contact us.

    Our Commitment to Quality

    We pride ourselves on our commitment to quality and we are certified to:

    • BSI ISO 9001: 2015
    • BSI ISO 14001: 2015

    We hold the ADS SC21 Bronze Award certification for supplying into the defence and aerospace industries.