Grommet
Grommets are used to reinforce holes in
leather,
clothing,
shoes, and other fabrics. They can be made of
metal or
plastic, and are easily used in common projects, requiring only the grommet itself, a metal rod with a convex tip (which usually comes with the grommets when you buy them in a store) and a hammer. Fancier grommet presses exist but generally a hammer works at least as well. Their most common usage is to strengthen the holes for bootlacing but are also good for making corsets and other laced clothing, plus curtains and other household items that require hanging from hooks. The grommet prevents the cord from tearing through the hole and thus provides structural integrity. Small grommets are also called eyelets, especially when used in clothing.