A pin is a device used for fastening objects or material together, and can have three 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), or 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.