0345 528 0474 Login or Register

How to choose the right grommet

clock 3.5 minutes | 12 Mar 2018

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, wood or plastic. Generally, a grommet is flared on both sides to hold it firmly in place. Grommets reinforce a hole and can provide cable protection for items passing through this hole. Take a look at our range of grommet types to help with your decision.

Sleeved grommets:

Can also be used to provide extra support and protection for cables and wires passing through panels. This is a function they perform across a number of applications, such as a data cabinet, electric cable enclosures, or machinery.

One of the most common use of grommets is in cable management, typically used to ensure safety and efficiency of cables and wires. Many businesses require cables to pass through desks, rack enclosure cabinets, server walls, cable enclosure and support systems and other solid objects. The solution adopted by many businesses is to cut a hole in the relevant surface and pass the cables through. This practice is potentially dangerous as rough or sharp edges can cause abrasion or sever the cables. This can have severe ramifications for a business as it can result in electrical shorts, production delays, or even fires. Grommets help to prevent these risks and ensure that wires and cables are protected and managed responsibly.

In the automotive industry, various rubber grommet sizes are used to seal important engine components and body applications. Without grommets, wires and cables would be shaken by the vibrations of the engine. This would cause the cables to repeatedly collide, or grate against the cable housing and vehicle components that they are passing through. Over time, this would cause wear and tear and possible severance of cables. Grommets hold the cables firmly in place and protect against vibration damage. Without automotive wiring protection, such as rubber grommets, vehicles would be significantly less reliable.

Standard grommets:

Snap-in design enables quick and easy installation. Depending on your application, material will factor into your decision. If you’re looking for as close to a heat proof material as you can get, you do have some choices.

Material
Why choose this grommet?
Black PVC Protect wires and cables passing through metal panels
Black TPR Resistant to most oils and greases
Withstands temperatures from -40C to +135C – grommets in this material work well with heat resistant cables
TPE Greener alternative to PVC
Suitable for harsh environments with operating temperature range from -40C to +135C
Good for high temperature electrical wire
Very stable material offering a long operating life
EPDM Heat-resistant material for use in extreme temperature environments from -40C to +125C
If using a high temperature cable, a grommet made of this material is a good choice


All products that involve vibrations or repetitive movement and cables will also benefit from an electrical wire protector. For example, industrial applications like HVAC components and industrial generator parts, or consumer appliances like washing machines and dishwashers all benefit from an extended lifespan thanks to the flexible cable protection grommets can offer.

IP67 Grommets

  • Provide a dust and watertight seal
  • Suitable for external applications
  • Acting as a blanking plug until a cable is installed
  • Can withstand vibrations


Membrane Entry Grommets

  • Attach to the edge of panels for easy access
  • Available in 3 styles in either Silicone Rubber or Nylon
  • Suitable for various shapes of cables

When designing products, it’s important that you consider cable management. If wires and cables are left to their own devices, with no thought to their care and organisation, that reflects poorly on your product and ultimately, on you.

Take for instance, an office desk. Do you really want customers jamming wires and cables down the back of that desk? Whilst this may answer an aesthetic issue, it can cause damage to their wires and cables. Rubbing on the edge of the desk or being squashed between two desks does their cables no favours and impacts their performance. A better solution is to incorporate desk grommets into your design to protect and extend the lifespan of your customers’ cables and wires whilst maintaining a safe and organised office. You should also look at cable hiding solutions, such as cable tidies and covers.

If it’s your customers’ data cabinet that you’re concerned with, consider the importance of their cables and wires. In essence, their data centre server cabinet holds a large amount of data, keeps them connected online, all while being responsible for a plethora of other critical technological assets. Looking after cables in this scenario is crucial as issues in this room can have significant business ramifications.

Some businesses have cables running under doors, and creeping around the edge of walls. Not only does this present a health and safety issue due to being a tripping hazard, but cables and wires are at risk of being crushed under foot, or by a door, being severed or clumping and being contracted which may present a fire risk. Again, by incorporating grommets into panels, you allow the cables to be separated and travel safely to their destination.

Other Grommet Types to consider:

Grommet Strips: Cable hiding system. Ideal for tight radii in panel cut-outs and holes.

Diaphragm Grommets contain a thin central film which can be pierced to allow a range of different-sized wires to pass through into an enclosure or through a panel.

  • One sided cut-outs have the central film to one side of the grommet.
  • Two sided cut-outs have the central film in the centre of the grommet

Stepped Grommets: The stepped sleeve can be cut to your specific requirements and can suit a range of cable diameters. They protect cables passing through panels and they act as a blanking plug until cut.

Grommets have a wide range of functions and benefits for businesses in just about all industries. They can save time, money and vital cable protection to help keep employees safe.

Cable Management - The Design Engineer's Application Guide