A ferrule is a name for types of metal objects, generally used for fastening, joining, or reinforcement. They are often narrow circular rings of metal, or less commonly, plastic.

Most ferrules consist of a circular clamp

Clamp (tool)

A clamp is a fastening device to hold or secure objects tightly together to prevent movement or separation through the application of inward pressure...

 used to hold together and attach fiber

Fiber

Fiber is a class of materials that are continuous filaments or are in discrete elongated pieces, similar to lengths of thread.They are very important in the biology of both plants and animals, for holding tissues together....

s, wire

Wire

A wire is a single, usually cylindrical, flexible strand or rod of metal. Wires are used to bear mechanical loads and to carry electricity and telecommunications signals. Wire is commonly formed by drawing the metal through a hole in a die or draw plate. Standard sizes are determined by various...

s or posts, generally by crimping, swaging

Swage

Swaging is a forging process in which the dimensions of an item are altered using a die or dies, into which the item is forced. Swaging is usually a cold working process; however, it is sometimes done as a hot working process....

, or otherwise deforming the ferrule to permanently tighten it onto the parts that it holds.

Examples

• The plastic sleeve preventing the ends of shoelaces from unraveling (called the aglet
  Aglet
  An aglet is a small plastic or metal sheath typically used on each end of a shoelace, cord, or drawstring. An aglet keeps the fibers of the lace or cord from unraveling; its firmness and narrow profile make it easier to hold and easier to feed through the eyelets, lugs, or other lacing...
  
  )
• The metal sleeve which is crimped to hold the eraser
  Eraser
  An eraser or rubber is an article of stationery that is used for rubbing out pencil markings. Erasers have a rubbery consistency and are often white or pink, although modern materials allow them to be made in any color. Many pencils are equipped with an eraser on one end...
  
   in place on pencil
  Pencil
  A pencil is a writing implement or art medium usually constructed of a narrow, solid pigment core inside a protective casing. The case prevents the core from breaking, and also from marking the user’s hand during use....
  
  s
• The metal band that binds the bristles or hair of a brush
  Brush
  A brush is a tool with bristles, wire or other filaments, used for cleaning, grooming hair, make up, painting, surface finishing and for many other purposes. It is one of the most basic and versatile tools known to mankind, and the average household may contain several dozen varieties...
  
   to its handle
• The metal ring which holds a chisel
  Chisel
  A chisel is a tool with a characteristically shaped cutting edge of blade on its end, for carving or cutting a hard material such as wood, stone, or metal. The handle and blade of some types of chisel are made of metal or wood with a sharp edge in it.In use, the chisel is forced into the material...
  
   blade's tang
  Tang (weaponry)
  A tang or shank is the back portion of a tool where it extends into stock material or is connected to a handle as on a knife, sword, spear, arrowhead, chisel, screwdriver, etc...
  
   to the handle
• In fiber optic terminations, glass or plastic fibers are bonded to precision ferrules and polished for splitting or connecting two fibers together
• The metal spike at the end of the shaft of an ice axe
  Ice axe
  An ice axe, is a multi-purpose ice and snow tool used by mountaineers both in the ascent and descent of routes which involve frozen conditions. It can be held and employed in a number of different ways, depending on the terrain encountered...
  
  
• The margin of a cast crown that stabilizes root-canal treated teeth in restorative dentistry
• The bottom end of a flag stick on a golf course, which fits snugly into a hole in the cup
• The plastic sleeve that adorns the bottom of most steel and graphite golf club shafts just above the club head hosel. Originally designed to protect the shaft from damaging vibrations, it is now used mainly for aesthetic purposes
• The metal band used to prevent the ends of wooden instruments from splitting
• The semi-circular metal band that holds the fibers in place on the Frog
  Bow (music)
  In music, a bow is moved across some part of a musical instrument, causing vibration which the instrument emits as sound. The vast majority of bows are used with string instruments, although some bows are used with musical saws and other bowed idiophones....
  
  s of bows
  Bow (music)
  In music, a bow is moved across some part of a musical instrument, causing vibration which the instrument emits as sound. The vast majority of bows are used with string instruments, although some bows are used with musical saws and other bowed idiophones....
  
   for violin family
  Violin family
  The violin family of musical instruments was developed in Italy in the sixteenth century. The standard modern violin family consists of the violin, viola, cello, and double bass....
  
   instruments
• Compression fitting
  Compression fitting
  Compression fittings are used in plumbing and electrical conduit systems to join two tubes or thin-walled pipes together. In instances where two pipes made of dissimilar materials are to be joined , the fittings will also be made of one or more compatible materials appropriate for the connection...
  
  s for attaching tubing (piping) commonly have ferrules in them.
• A swaged termination type for wire rope
• The cap at the end of a cane or umbrella.
• The portion of a cue
  Cue stick
  A cue stick , is an item of sporting equipment essential to the games of pool, snooker and carom billiards. It is used to strike a ball, usually the...
  
   in pool, billiards and snooker that tops the and to which the is bonded; historically made of ivory
  Ivory
  Ivory is a term for dentine, which constitutes the bulk of the teeth and tusks of animals, when used as a material for art or manufacturing. Ivory has been important since ancient times for making a range of items, from ivory carvings to false teeth, fans, dominoes, joint tubes, piano keys and...
  
  , now typically made of fiberglass
  Fiberglass
  Glass fiber is a material consisting of numerous extremely fine fibers of glass.Glassmakers throughout history have experimented with glass fibers, but mass manufacture of glass fiber was only made possible with the invention of finer machine tooling...
  
  , phenolic resin or brass
  Brass
  Brass is an alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties.In comparison, bronze is principally an alloy of copper and tin...
  
  
• The male and female joints that join one section of a two-piece fishing rod
• A metal cap at the end of cable housing with a hole on bicycle or motorcycle control cables
• The metal sleeve that connects a hypodermic needle
  Hypodermic needle
  A hypodermic needle is a hollow needle commonly used with a syringe to inject substances into the body or extract fluids from it...
  
   to a plastic luer taper (which then connects to a syringe
  Syringe
  A syringe is a simple pump consisting of a plunger that fits tightly in a tube. The plunger can be pulled and pushed along inside a cylindrical tube , allowing the syringe to take in and expel a liquid or gas through an orifice at the open end of the tube...
  
   or intravenous therapy
  Intravenous therapy
  Intravenous therapy or IV therapy is the infusion of liquid substances directly into a vein. The word intravenous simply means "within a vein". Therapies administered intravenously are often called specialty pharmaceuticals...
  
   tubing.)
• A metal tube crimped
  Crimp connection
  A crimp connection is achieved with a type of solderless electrical connector.Crimp connectors are typically used to terminate stranded wire. They fulfill numerous uses, including allowing the wires to be easily terminated to screw terminals, fast-on / quick-disconnect / spade-foot type terminals,...
  
   over stranded wire to secure it within a screw terminal
  Screw terminal
  A screw terminal is a type of electrical connector where a wire is clamped down to metal by a screw.The wire is sometimes just stripped of electrical insulation at the end, and is bent in a U or J shape to fit around the shaft of the screw....
  
   usually with electrical insulation
  Electrical insulation
  thumb|250px|[[Coaxial Cable]] with dielectric insulator supporting a central coreThis article refers to electrical insulation. For insulation of heat, see Thermal insulation...
  
  protecting any exposed portion of the wire not completely inside the screw terminal post.