What is a grommet? What are the types of grommets?

Messy monitor wires needing cable management grommets

A grommet is a circular tube or ring that is typically inserted into a hole in a thin material such as metal, plastic or rubber. Generally, a grommet is flared on both sides to hold it firmly in place. But what is the purpose of grommets? This guide answers that question, while also covering:

What is a grommet used for?
Different types of grommets 
What are grommets made from?

What is a grommet used for?

Grommets serve several purposes. They reinforce holes in panels that might otherwise be prone to tearing, fraying, or wear and tear due to friction or exposure to stress. 
 

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They’re used in cable management, enabling cables to pass through panel holes, as shown with this stepped grommet, part of our range of grommets. You can download free CADs now for a closer look. 

You should always consider using a grommet in electrical applications. Grommets protect the cables from sharp edges while also preventing kinks and tangling. In applications where materials rub against each other, grommets are especially helpful.
 

Think of vibrations or repetitive movement that occurs in industrial applications, like HVAC components and industrial generator parts, or consumer appliances such as washing machines and dishwashers. All enjoy an extended lifespan, thanks to the flexible cable protection grommets offer.

A grommet can also provide a seal against air, water, or dust, helping to maintain environmental integrity and provide insulation. This is the sole purpose of blanking grommets, also called blind grommets. These are not used to protect cables, but to seal panel holes. 

You can learn more about cable protection in our guide, Making Cable Management Easier – A Buyer’s Guide. 

What are grommets used for in cars?

Grommet function when it comes to cars serves two purposes. One, they protect cables from rubbing on rough surfaces. They’re typically used under the bonnet to seal engine components. When continuous and hard shaking is involved – as it is with an engine – you should always use cable and wire grommets that can withstand high temperatures. They’re also used in the car’s wiring harness. A grommet wiring harness comprises the wires, terminals and connectors that relay electrical signals to various components. 

Car grommets on the vehicle’s body are another type. The grommet purpose here is to seal access holes and prevent ingress. These are called blind grommets, or blanking grommets. 

We work with the top 15 global tier-one automotive suppliers. If you need help choosing the right grommet, our experts are happy to advise you. Call 0345 528 0474.

Different types of grommets

From managing cables to reinforcing openings, different grommet types are designed for specific needs. Let’s look at our range of grommets that cater to different industries, and their purpose.
 

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Grommet Sleeves
Used to provide extra support and protection for cables and wires passing through panels in data cabinets, electric cable enclosures, or machinery. Made of PVC.
 

Standard Open Grommets
Snap-in design enables quick and easy installation. Popular for automotive and electronic applications, they prevent pull though, ensuring the integrity of your assembly. Open rubber grommets, as they’re also known, are available in TPR, PVC, EPDM, and TPE. 
 

IP67 Sealing Grommets

Commonly used in applications where environmental sealing and protection are critical, such as outdoor enclosures. The IP67 rating means these grommets are highly resistant to dust, debris, and water ingress, making them suitable for use in challenging and demanding conditions. Also stands up to vibration and acts as a blanking plug until cables are installed. Made of EPDM.
Also stands up to vibration and acts as a blanking plug until cables are installed. Made of EPDM.

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Membrane Entry Grommets 
Cable Grommet allows multiple cables and wires to pass through, while offering protection from sharp edges and protects against ingress. Helps keep cables tidy and organised. Typically used for electrical enclosures, data centres, control panels, industrial machinery, and solar power applications. Nylon 6/6 or black silicone grommets available. 
 

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Grommet Strips
Another type of grommet is a grommet strip. This is used to route and protect cables, wires, hoses, and tubing, ensuring a neat and organised appearance while preventing tangling, wear, and potential damage. Available in TPE, LDPE, nylon, nylon 6/6, stainless steel with nylon coating, or polystyrene. 

Diaphragm Grommets
Diaphragm grommets contain a thin central film that can be pierced to allow a range of different sized wires to pass through into an enclosure or through a panel. Two sided cut-outs have the central film in the centre of the grommet, whereas one sided cut-outs have the film to one side of the grommet. Ideal wiring grommets for automotive, telecommunications equipment, and control panels. Made of PVC.

Stepped Grommets
The angular hole allows the wire to pass through at an angle of up to 45 degrees. Great for automotive wiring, electrical panels and enclosures, and medical devices. Available in EPDM and PVC. 

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What are grommets made from?

You’ve just seen the variety of materials grommets come in. The next question is, what’s the right grommet to use for your application? That sometimes comes down to the material it’s made of. A silicone grommet is very different from a nylon grommet, for example. In fact, some plastic grommets can give you the same characteristics as rubber cable grommets. 

You can learn more in our Guide to Rubber Grommets. 
 

Download free CADs and try before you buy

Free CADs are available for most solutions, which you can download. You can also request free samples to make sure you’ve chosen exactly what you need. If you’re not quite sure which solution will work best for your application, our experts are always happy to advise you.

Whatever your requirements, you can depend on fast despatch. Request your free samples or download free CADs now.

Questions?

Email us at sales@essentracomponents.co.uk or speak to one of our experts for further information on the ideal solution for your application 0345 528 0474.