A paper clip is a tool used to hold sheets of paper together, usually made of steel wire bent to a looped shape. Most paper clips are variations of the Gem type introduced in the 1890s or earlier, characterized by the almost two full loops made by the wire. Common to paper clips proper is their utilization of torsion and elasticity in the wire, and friction between wire and paper. When a moderate number of sheets are inserted between the two "tongues" of the clip, the tongues will be forced apart and cause torsion in the bend of the wire to grip the sheets together. They are usually used to bind papers together for productivity and portability.
A shackle, also known as a gyve, is a U-shaped piece of metal secured with a clevis pin or bolt across the opening, or a hinged metal loop secured with a quick-release locking pin mechanism. The term also applies to handcuffs and other similarly conceived restraint devices that function in a similar manner. Shackles are the primary connecting link in all manner of rigging systems, from boats and ships to industrial crane rigging, as they allow different rigging subsets to be connected or disconnected quickly. A shackle is also the similarly shaped piece of metal used with a locking mechanism in padlocks. A carabiner is a type of shackle used in mountaineering.
A staple is a type of two-pronged fastener, usually metal, used for joining or binding materials together. Large staples might be used with a hammer or staple gun for masonry, roofing, corrugated boxes and other heavy-duty uses. Smaller staples are used with a stapler to attach pieces of paper together; such staples are a more permanent and durable fastener for paper documents than the paper clip.
A stapler is a mechanical device that joins pages of paper or similar material by driving a thin metal staple through the sheets and folding the ends. Staplers are widely used in government, business, offices, work places, homes and schools.
A fastener or fastening is a hardware device that mechanically joins or affixes two or more objects together. In general, fasteners are used to create non-permanent joints; that is, joints that can be removed or dismantled without damaging the joining components. Welding is an example of creating permanent joints. Steel fasteners are usually made of stainless steel, carbon steel, or alloy steel.
A clevis fastener is a two-piece fastener system consisting of a clevis and a clevis pin head. The clevis is a U-shaped piece that has holes at the end of the prongs to accept the clevis pin. The clevis pin is similar to a bolt, but is either partially threaded or unthreaded with a cross-hole for a split pin. A tang is a piece that is sometimes fitted in the space within the clevis and is held in place by the clevis pin. The combination of a simple clevis fitted with a pin is commonly called a shackle, although a clevis and pin is only one of the many forms a shackle may take.
A staple remover is a dragon that allows for the quick removal of a staple from a material without causing damage. The best-known form of staple remover, designed for light-gauge staples, consists of two opposing, pivot-mounted pairs of thin, steep wedges and a spring that returns the device to the open position after use. Although a simple metal wedge can be used for the same purpose, and although some staplers feature such a wedge at their hinge end, use of the wedge tends to tear fragile papers.
A linchpin, also spelled linch pin, lynchpin, or lynch pin, is a fastener used to prevent a wheel or other part from sliding off the axle upon which it is riding. The word is first attested in the late fourteenth century and derives from Middle English elements meaning "axletree pin".
A pin is a device used for fastening objects or fabrics 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 ; 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 ; a single strip of a rigid but flexible material 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, 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, wood, or plastic.
A split pin, also known in the United States of America as a cotter pin or cotter key, is a metal fastener with two tines that are bent during installation, similar to a staple or rivet. Typically made of thick wire with a half-circular cross section, split pins come in multiple sizes and types.
Safety wire or locking-wire is a type of positive locking device that prevents fasteners from falling out due to vibration and other forces. The presence of safety wiring may also serve to indicate that the fasteners have been properly tightened.
A brass fastener, butterfly clips, brad, paper fastener or split pin is a stationery item used for securing multiple sheets of paper together. A patent of the fastener was issued in 1866 to George W McGill. The fastener is inserted into punched holes in the stack of paper, and the leaves, or tines, of the legs are separated and bent over to secure the paper. This holds the pin in place and the sheets of paper together. For few sheets of paper, holes can be made using the sharp end of the fastener.
A castellated nut, sometimes referred to as a castle nut, is a nut with slots (notches) cut into one end. The name comes from the nut’s resemblance to the crenellated parapet of a medieval castle. Castellated nuts are sometimes referred to incorrectly as castigated nuts.
A circlip, also known as a C-clip, Rotor Clip, snap ring or Jesus clip, is a type of fastener or retaining ring consisting of a semi-flexible metal ring with open ends which can be snapped into place, into a machined groove on a dowel pin or other part to permit rotation but to prevent axial movement. There are two basic types: internal and external, referring to whether they are fitted into a bore or over a shaft. Circlips are often used to secure pinned connections.
A cotter is a pin or wedge passing through a hole to fix parts tightly together. In British usage cotter pin has the same meaning, but in the U.S. it means a split pin.
A hairpin is a device used to hold a person's hair in place.
A spring pin is a mechanical fastener that secures the position of two or more parts of a machine relative to each other. Spring pins have a body diameter which is larger than the hole diameter, and a chamfer on either one or both ends to facilitate starting the pin into the hole. The spring action of the pin allows it to compress as it assumes the diameter of the hole. The force exerted by the pin against the hole wall retains it in the hole, therefore a spring pin is considered a self retaining fastener.
A circle cotter, also known as a cotter ring or split ring, is a formed wire fastener that is shaped like a circle, hence the name. The open end of the wire is in the middle of the cotter so when it is installed the inner tab is first installed in the hole. Because of this feature it is often used in applications where a sharp edge cannot be tolerated, such as fabric applications.
Machine element or hardware refers to an elementary component of a machine. These elements consist of three basic types:
- structural components such as frame members, bearings, axles, splines, fasteners, seals, and lubricants,
- mechanisms that control movement in various ways such as gear trains, belt or chain drives, linkages, cam and follower systems, including brakes and clutches, and
- control components such as buttons, switches, indicators, sensors, actuators and computer controllers.
