Pin

A pin is a device used for fastening objects or fabrics together. Pins can have the following sorts of body: a shaft of a rigid inflexible material meant to be inserted in a slot, groove, or hole (as with pivots, hinges, and jigs) a shaft connected to a head and ending in a sharp tip meant to pierce one or more pieces of soft materials like cloth or paper (the straight or push pin) a single strip of a rigid but flexible material (e.g. a wire) whose length has been folded into parallel prongs in such fashion that the middle length of each curves towards the other so that, when anything is inserted between them, they act as a clamp (e.g. the bobby pin) two strips of a rigid material bound together by a spring at one end so that, when the spring held open, one can insert some material between the prongs at the other end that, the spring allowed to close, then clamp the inserted material. According to their function, pins can be made of metals (e.g. steel, copper, or brass), wood, or plastic. Pins have been found at archaeological sites dating as early as the Paleolithic, made of bone and thorn, and at Neolithic, Celtic and Ancient Roman sites. Neolithic sites are rich in wooden pins, and are still common through Elizabethan times. Metal pins dating to the Bronze Age have been found in Asia, North Africa and Europe, like the hammer-headed pins from the kurgan burials in the northeastern Caucasus. The development of the pin closely paralleled that of its perforated counterpart, the needle. Archaeological evidence suggests that curved sewing pins have been used for over four thousand years. Originally, these were fashioned out of iron and bone by the Sumerians and were used to hold clothes together. Later, pins were also used to hold pages of books together by threading the needle through their top corner. Many later pins were made of brass, a relatively hard and ductile metal that became available during the Bronze Age. This development was followed by the use of steel which was much stronger but tended to rust when exposed to humid air.