A pin is a device used for fastening objects or material together. It is usually made of steel

Steel

Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...

, or on occasion copper

Copper

Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

 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...

. It is formed by drawing out a thin 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...

, sharpening the tip, and adding a head. Nails are related, but are typically larger.

History

Curved pins have been used for over four thousand years. Originally, they were fashioned out of iron and bone by the Sumerians and were used to hold clothes together. Later, these pins were also used to hold pages together by threading the needle through their top corner.

Many late pins were made of brass, a hard metal. Steel was used later, as it was much stronger, but there was no easy process to keep steel from rusting, so higher quality pins were plated with nickel, but the metal would start to break down and flake off in high humidity, allowing rust to form. Steel pins were not that inconvenient for homemaking uses as they were usually only used temporarily while sewing garments.

Other types

The push pin, with a large plastic head, was invented in 1903 by Edwin Moore and quickly became a success. These pins are also called "thumbtack

Thumbtack

A drawing pin , thumbtack , or push pin is a short nail or pin with a circular, sometimes domed, head, used to fasten items such as documents to a wall or board for display. Various designs and names are used. They are inserted and removed by hand, hence the terms "thumbtack" and "push pin"...

s". There is also a new push pin called a "paper cricket".

Walter Hunt

Walter Hunt

Walter Hunt was an American mechanic. He lived and worked in New York state. Through the course of his work he became renowned for being a prolific inventor, notably of the lockstitch sewing machine , safety pin , a forerunner of the Winchester repeating rifle, a successful flax spinner, knife...

 invented the safety pin

Safety pin

A safety pin is a simple fastening device, a variation of the regular pin which includes a simple spring mechanism and a clasp. The clasp serves two purposes: to form a closed loop thereby properly fastening the pin to whatever it is applied to, and to cover the end of the pin to protect the user...

 by forming an eight-inch brass pin into a bent pin with a spring and guard. He sold the rights to his invention to pay a debt to a friend, not knowing that he could have made millions of dollars.
In engineering and machine design, a pin is a machine element that secures the position of two or more parts of a machine relative to each other. A large variety of types has been known for a long time, the most commonly used are solid cylindrical pins, solid
tapered pins, groove pins, slotted spring pins and spirally coiled spring pins.

See also

• Bobby pin
  Bobby pin
  A bobby pin is a type of hairpin. In British English, it is known as a hair grip, grip, or kirby grip. It is a small pin or clip, usually of metal or plastic, used in coiffure to hold hair in place. Typical bobby pins are plain and unobtrusively colored, but some are elaborately decorated or jeweled...
  
  
• Clevis pin
  Clevis pin
  A clevis fastener is a three piece fastener system consisting of a clevis, clevis pin, and tang. 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 only partially threaded or unthreaded with a cross-hole for a...
  
  
• Collar pin
  Collar pin
  A collar pin is a piece of men's jewelry that holds the two ends of a dress shirt collar together and passes underneath the knot of a necktie...
  
  
• Cotter pin
  Cotter pin
  A split pin, also known in U.S. usage 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.The British...
  
  
• Hairpin
  Hairpin
  A hair pin or hairpin is a long device used to hold a person's hair in place.Hairpins made of metal, ivory, bronze, carved wood, etc. were used in ancient Assyria and Egypt for securing decorated hairstyles. Such hairpins suggest, as graves show, that many were luxury objects among the Egyptians...
  
  
• Lapel pin
  Lapel pin
  A lapel pin is a small pin often worn on the lapel of a dress jacket. Lapel pins can be purely ornamental or can indicate the wearer's affiliation with an organization or cause; for example, American Flag lapel pins became very popular in the United States, especially among politicians, following...
  
  
• Push pin
• Safety pin
  Safety pin
  A safety pin is a simple fastening device, a variation of the regular pin which includes a simple spring mechanism and a clasp. The clasp serves two purposes: to form a closed loop thereby properly fastening the pin to whatever it is applied to, and to cover the end of the pin to protect the user...
  
  
• Spring pin
  Spring pin
  A spring pin is a mechanical fastener that secures the position of two or more parts of a machine relative to each other...
  
  
• Microperforation
• Hot needle perforation
• Paper cricket
• Split pin