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. Fluorocarbon Rubber Most grommets are made from rubber, but plastic grommets are available in the UK and elsewhere, along with models made from other materials, including: Open rubber grommets are the most basic design, featuring a central hole. They are used to protect cables and pipes when they pass through holes in metal plating. Closed Rubber Grommets 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. Neoprene Also known as blind rubber grommets, closed grommets provide air-tight seals when applied, and can be a good choice for sealing holes not currently in use to prevent the build-up of dust.

Grommet strips are strips of material that sit over the edge of a panel. They are designed to improve the appearance or to protect the edge. Grommet strips are available in various lengths which are often able to be cut to size. There are heat-activated adhesive strips available too. Some feature a small hole into which a wire can be inserted for a firm hold. These are called diaphragm grommets. Open Rubber Grommets Round/Oval Grommets fit inside of holes that are cut into panels. They are often used to protect cables from sharp cut edges or to provide strain relief for the cable. When a hole is cut into a panel, it can often leave a sharp edge. The grommet not only makes it look better but also acts as a bumper for cables and wire that pass through. Most round/oval grommets fit by pushing or snapping into place. Blind/Blanking grommets are the same as round grommets however they do not have a hole in the middle. They are often used to fill holes that are not currently in use to prevent dust from getting in. Some blanking grommets have a small holes in them. These are referred to as diaphragm grommets. The hole sits snug around the wire to protect it from the surrounding area and to prevent dust from passing through to the electrics behind it. 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. SiliconeRubber grommets are available in several different types. Here are the principal ones: Rubber Blanking Plugs Rubber blanking plugs are used to seal holes and are designed to hold and control pressure coming from above or below, making them a good grommet choice for high-pressure UK devices and tubing. This offers good tensile strength and resistance to strain and tears, along with strong electrical insulation. Nitrile Rubber Unlike similarly shaped round grommets, blind rubber grommets have no central hole. They are widely used by the UK electronics industry.