A hole puncher is an office tool that punches small round holes into the edges of paper so that the paper can be inserted into a loose-leaf binder. Hole punchers can be small items that punch one hole at a time, 12-inch long machines that punch three holes for North American binders, or devices that punch two holes in order to fit two-ring binders used in the United Kingdom.
The working center of a hole puncher is the punch. This is a small, round piece of solid metal measuring ¼ inch in diameter. It has sharp edges on its bottom end, and its top end is attached to the lever. There is one punch on a one-hole puncher and three punches – each separated by a space of four inches – on a three-hole puncher.
The surface of a hole puncher has strategically placed holes through which the punches pass when the lever is depressed. By placing one or several pieces of paper on top of the holes, and then depressing the lever, the user is able to drive the punches through the paper and into the holes. Because the punches fit tightly into the holes, the pressure shears the paper off where the punch and the hole meet, leaving a perfectly round hole in the paper.
The lever is on top of the assembly, with the punches attached to its underside. On a three-hole puncher, the lever runs the length of the assembly and depresses all three punches at the same time, thus saving time and ensuring that the holes will be the same distance apart on all pieces of paper. The mechanism works by placing the puncher on a desktop, inserting a maximum of eight or 10 pieces of paper into the puncher so that the edges of the piece of paper line up on a fence next to the hinge of the puncher, and firmly depressing the lever in order to drive the punches downward.
Most hole punchers have a removable cover on the bottom, creating a small reservoir where the small round bits of scrap are caught. This prevents a person's office from becoming littered with tiny bits of paper. When the reservoir becomes full, the bottom cover is easily removed in order to empty the bits of paper into the recycling bin.