Whether crafting, building furniture, or simply adding another hole in your belt, it may be necessary to cut or punch a hole in a piece of leather. Leather is very tough, but the hole needs to be reinforced with a metal eyelet or grommet. Most commonly made of brass, aluminum or steel, eyelets and grommets protect the inside diameter of the hole from abrasion, cuts and tears. An eyelet is one piece of circular metal that is peened, or curled, over and is used on thick, tough leather. A grommet is similar, but consists of two pieces: an eyelet and a washer. It is used on thinner leather. The wider surface area of the washer gives the soft leather better protection.
Select the leather punch closest in size to but larger than the existing hole or tear in the leather.
Place the leather on top of the wood block. Place the punch around the hole and tap down firmly with a hammer. The punch will cut a clean, perfectly circular hole.
Insert the eyelet or grommet closest in size into the hole in the leather.
Place the wide side of the eyelet or grommet facedown on top of the appropriate die. If you are installing a grommet, place the washer on to the shank of the eyelet from the top. The grommet should now have two wide rings -- one on each side -- of the leather, sandwiching it.
Place the rounded point of the driver into the hole in the shank of the eyelet and tap down repeatedly until the straight shank is peened over. With just an eyelet, the peened portion clamps down onto the leather. With a grommet, the peened portion clamps down on the washer.