Hole punch

A hole punch (also known as a hole puncher) is a common office tool that is used to create holes in sheets of paper, often for the purpose of collecting the sheets in a binder or folder. A leather punch, of different construction from one designed for paper, is used for leather goods, cloth, or thin plastic sheeting. Hole punch tools are also made for use on sheet metal, such as aluminum siding or metal air ducts.

A typical hole punch, whether a single or multiple hole punch, has a long lever which is used to push a bladed cylinder straight through a number of sheets of paper. As the vertical travel distance of the cylinder is only a few millimeters, it can be positioned within a centimeter of the lever fulcrum. For low volume hole punches, the resulting lever need not be more than 8 centimetres (3.1 in) for sufficient force.

Two paper guides are needed to line up the paper: one opposite where the paper is inserted, to set the margin distance, and one on an adjacent side.

Hole punches for industrial volumes (hundreds of sheets) feature very long lever arms, but function identically.

Another mechanism uses hollowed drills which are lowered by a screwing action into the paper. The paper is cut and forced up into the shaft of the drill to be later discarded as tightly packed columns of waste paper. This method allows a small machine to cut industrial volumes of paper with little effort.

The most common standard for the dimensions and location of filing holes punched in paper is International Standard ISO 838. Two holes with a diameter of 6±0.5 mm are punched into the paper. The centers of these holes are 80±0.5 mm apart and have a distance of 12±1 mm to the nearest edge of the paper. The holes are located symmetrically in relation to the axis of the sheet or document.

Any paper format that is at least 100 mm high (e.g. ISO A7 and larger) can be filed using this system. A printed document with a margin of 20–25 mm will accommodate ISO 838 filing holes.

A four-hole extension is also commonly used. The two middle holes are punched in accordance with ISO 838, and so paper punched with the four holes can be filed in binders that are consistent with ISO 838. The two additional holes are located 80 mm above and below these. The use of two additional holes provides more stability. This extension is sometimes referred to as the "888" system, because of the three 8-cm gaps between the holes. Some 2-hole punches have an "888" marking on their paper guide, to assist punching all four holes into A4 paper.

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