Grommets, sometimes referred to as edging, are pieces of plastic or rubber which cover an edge for functional or aesthetic purposes. Grommets are commonly used in electrical installations, for example, metal back boxes. They are used when wires need to pass through a panel, or where edges need smoothing.
What are they made from?
Most grommets are made from either plastic, rubber or Nylon. PVC is a popular material as it is strong and durable. Most cable grommets are black but there are other colours available, such as clear or grey.
What types of cable grommet are there?
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 than pass through. Most round/oval grommets fit by pushing or snapping into place.
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.
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 hole 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.
How to choose a grommet:
If you are looking for round grommets, you need to consider the panel and the hole it is to sit in. The grommet needs to match the same size as the panel hole diameter and the thickness of the panel. The inner hole diameter also needs to meet your specification of how large the wires that pass through will be. Most measurements for grommets are given in millimetres (mm).
If you are considering a grommet strip/edging, the strip needs to fit over the width of the edge of the panel. You also need to ensure that the strip is long enough to cover your desired edge. Most strips can be cut down to size if required.