Most grommets are made from rubber, but plastic grommets are available in the UK and elsewhere, along with models made from other materials, including:
Different types of grommet rubber are also used. These include:
This offers good tensile strength and resistance to strain and tears, along with strong electrical insulation.
Also known as Buna-N, nitrile rubber is highly oil-resistant. This makes it the first choice for grommets when exposure to oil is a possibility. Electrically, it is a semiconductor (a substance with electrical conductivity halfway between an insulator and a metal) and is also antistatic.Additionally, if the grommets are made from NBR nitrile rubber, there is a mechanical industry standard that indicates a shelf life of 4-5 years.
Also known as FKM or Viton, fluorocarbon rubber is a particularly stable rubber effective that can withstand high temperatures and strongly acid or alkali environments.
This resilient material is resistant to heat, flame, ozone corrosion and weather, making it a good choice for use outdoors and in areas of fire risk.
Silicone offers bright colours and it is a friendlier material than some other rubbers. It is odourless and perfectly safe when in contact with food and skin, so silicone grommets are frequently used in kitchen devices, food processing machines and medical equipment.