An Introduction to Grommets and How They Work


From jeans and boots to cable housings and computers, grommets are found in many everyday products. Also known as eyelets, they are designed to fit inside of a precut hole. While you’ve probably used products containing a grommet, though, you might be wondering how they work. Below is an introduction to grommets that reveals their basic mechanics and purpose.

What Is a Grommet?

A grommet is a thin and small ring-shaped piece of material that’s placed inside a pre-cut hole. They look like O-rings. While O-rings are typically used to seal a connection between two or more passages, grommets are not. Grommets are placed inside pre-cut holes for other reasons.

Most grommets are flared on the sides. With flared sides, they offer a more secure fit when placed inside a pre-cut hole. The flared sides hold the grommet in place so that it’s less likely to move around and, therefore, fall out. You can find grommets with straight sides, but most of them have flared sides for increased security.

Some of the most common materials in which grommets are made include the following:

  • Plastic
  • Rubber
  • Aluminum
  • Steel
  • Copper

What Are Grommets Used For?

Grommets are used in many different applications, one of the most common being cable housings. Metal machines and equipment often have electrical wires that run through them. When a hole is cut in a metal machine or piece of equipment for an electrical cable, a grommet may be used to protect the cable from damage. Without a grommet, the cable will be exposed to the hole’s jagged edges. If the cable rubs against these jagged edges, it may fail. A simple solution is to place a grommet inside the hole. The grommet will cover the hole’s otherwise jagged edges with a soft piece of material, thereby protecting the cable from potential damage.

You’ll often find grommets in shoes, boots and other types of footwear. In footwear, grommets are used to contain shoelaces. They’ll have at least one pair of grommets at the top and potentially several more pairs below. While they offer some level of protection, grommets are typically used for aesthetic purposes in footwear.

Computers may contain one more grommets as well. Hard-disk drives (HDDs), specifically, may be mounted with grommets to minimize vibrations. While newer solid-state drives (SSDs) don’t require them, HDDs produce heavy vibrations that can cause premature failure. Grommets help to reduce vibrations so that HDDs don’t fail prematurely. These are just a few applications in which grommets are used.

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