A pin is a device used for fastening objects or material together. Pins often have two components: a long body and sharp tip made of steel, or occasionally copper or brass, and a larger head often made of plastic. The sharpened body penetrates the material, while the larger head provides a driving surface. It is formed by drawing out a thin wire, sharpening the tip, and adding a head. Nails are related, but are typically larger. In machines and engineering, pins are commonly used as pivots, hinges, shafts, jigs, and fixtures to locate or hold parts.
Sewing and fashion pins
Curved sewing 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.
The term "pin money" dates to the 17th century; according to Oxford University Press, it refers to an allowance for decorative clasps that were worn in hair or on clothing. It was subsequently applied to money to buy clothing generally, and later to money for any minor personal expenditure.
Walter Hunt invented the safety pin 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.
Bobby pins and other types of hairpins are used for restraining the hair. Collar pins are used to hold the collar of a dress shirt in men's fashion. Lapel pins are decorative jewelry attached to the clothing.
General purpose pins
Steel pins without heads
Thin, hardened pins can be driven into wood with a hammer with the goal of not being seen.
A different style pin, somewhat thicker (1.5–2 mm diameter), 2 cm short and with rounded tip (known as a stylus) is used with gramophones. The vibration of the stylus transforms the physical waves of the groove in a record to the movement of a membrane. In this way the sound recorded can be heard.
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.
- Petroski, Henry, "From Pins to Paper Clips", The Evolution of Useful Things, Knopf, New York, 1993, p. 53
- Bridgman, Roger. 1000 Inventions & Discoveries. New York: Dorling Kindersley Publishing , 2002, p.126
- "Pin Money". Oxford Dictionaries. Oxford UP. Retrieved 26 November 2013.
- The Phrase Finder : Pin Money. Retrieved 2012-09-22.
- Alfred, R (2008-10-04). "April 10, 1849: Safety Tech Gets to the Point, Baby". Wired. Retrieved 2008-10-23.
- Henry Petroski, The Evolution of Useful Things, Chapter 4. ISBN 0-679-74039-2.
- Robert Parmley, Standard handbook of fastening and joining. 1st edition. Chapter 2. McGraw-Hill (New York). 1977. ISBN 0-07-048511-9