What Are Grommets ? How Are They Used ?

Technically speaking, grommets are small collared or flared rings made of rubber, plastic or metal. They are normally used for preventing abrasions or tearing of materials, or for covering sharp edges. The very small ones are also known as eyelets and are used in a wide range of items such as shoes, fabrics, bags, etc.

In projects involving usage of cloth, leather, canvas, shoes or other fabric, grommets are usually used for reinforcing holes within the material. They are set in position with the help of a punch and a hammer that is striked on the head of the punch. The cords passed through the grommets therefore, cannot tear through the holes and structural integrity of the material is conserved. The eyelets are used more commonly in crafting or clothing, sometimes completely for the purpose of decoration.

If metal, wood, or other similar hard material has hole drilled through it, it would obviously have sharp edges. Electrical wires, rope, cords, etc. passing through it can get cut or abraded due to repeated flexing. To prevent this from happening, cable grommets are used. A cable grommet is usually made of plastic, rubber or metal and can effectively protect the cords or ropes from abrasions and dirt. The ones made of plastic also have lids that can be snapped shut to keep the wires in place. They are manufactured in a wide range of sizes, shapes and colours. Some also come with a flexible extension that is moulded or tapered and can flex increasingly near the free end for reducing the breakage of insulation on electrical wires.

Grommets manufactured using elastic materials, such as rubber, are also utilised for reducing the transfer of vibrations. They were popularly used to mount computer disk drives which are shock-sensitive, especially in equipment vulnerable to jarring or vibration. Nowadays, however, modern drives are more robust and do not use this strategy. But a similar method is followed for isolating electronic circuit components sensitive to microphonism acoustically.

In cases of severe otitis media that are characterised by presence of effusions for months, a type of grommet known as tympanostomy tube is surgically inserted in the eardrum for allowing passage of air in the middle ear. This helps in clearing excess fluid and releasing pressure buildup, if any. The same method is also adopted for correcting patulous Eustachian tube, a condition characterised by to and fro motion of air with every breath, which makes the eardrum flap.