Staplers come in many sizes and shapes, and have just as many uses. Staplers are used in the manufacturing of many types of furniture, the laying of carpet, the closing of certain wounds after medical procedures, attaching electrical wiring, installing of insulation, the construction of many types of picture frames, and of course, the many uses in the home and office environments. The primary focus of this article is the basic office stapler.
The basic parts of a stapler include the arm which is attached to the base, most commonly with a metal pin, the magazine cartridge which contains the carriage that holds the staples, a guide spring that feeds the staples to the front of the stapler, a tooth that pushes down on the staples when the arm is pressed, and a leaf style spring that returns the arm to its resting position once a staple has been pressed. Depending on the size of the stapler, the base can either be a solid formed piece of sheet metal, or can contain a spring controlled plate which sits under the spot where the staples come out. This plate can be rotated to control whether the arms of the staple fold in, as is the most common direction, or fold outward, which has been found to accommodate more sheets of paper.
Most parts of staplers these days are machine manufactured. The arm and base, depending on the size of the stapler, can be made of injection-molded plastic, a process in which liquid plastic is injected into a large collection of pre-shaped metal molds that, once the plastic is cooled, form the plastic into the needed shape. They can also be stamped out of various thicknesses of sheet metal, a process that involves large sheets of metal, usually steel or aluminum, that move through a series of machines that first cut out the basic shape of the parts needed and then, using large hydraulic presses, bend and shape the metal into the desired shape. The coiled springs are made by a series of machines that take long spools of wire with various diameters, cut the wire to length, coil them to the necessary shape and finally heat-treats them to give them their spring properties. All other parts of the stapler are stamped out of sheet metal. The individual pieces are assembled by hand, with the assistance of machines that close the rivets and make sure the pieces fit tightly together.