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A thumbtack (known as a drawing-pin in the UK, India, Australia and New Zealand) is a short nail or pin with a large, slightly rounded head made of metal which is used to fasten documents to a background for public display and which can easily be inserted or removed by hand.
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Types of Thumbtack
The most common thumbtacks are made by attaching a brass stem to a flat brass head. Some have coloured plastic tops, to make them more attractive.
Map Pins, or push pins, are not a type of thumbtack. Map Pins have a handle-like cover of plastic, which brings the pin out of the wall, allowing quick and easy removal from surfaces. Some other map pins have a round 1mm head to allow for easy removal. Both types come in a variety of colors. Map pins are safer than flat-headed thumbtacks when dropped on the ground or discarded on a surface, since they will not normally rest with the point upward.
History
The map pin was invented by Edwin Moore around 1900, the year in which he founded the Moore Push-Pin Company [1].
As far as is currently known, the thumbtack was invented by the clockmaker Johann Kirsten in the year 1903 in the town of Lychen in Uckermark, Germany [2]. He sold the rights to the invention to Otto Lindstedt, a businessman, who received a patent for the thumbtack on 8th January 1904. Lindstedt became a wealthy man while Kirsten, the clockmaker, remained in poverty. Other sources ascribe the invention of the thumbtack to Austrian factory owner Heinrich Sachs in 1888 [3].
Physics
A thumbtack can be inserted by hand because of the large area of its head relative to the area of its point. When a relatively low pressure is applied across the large head of a thumbtack, a high pressure will be applied by the tip of the thumbtack. The low pressure on the head means the thumbtack will not pierce a person's finger. The high pressure at the tip allows it to pierce the surface to which the document is being fastened.
Facts
A thumbtack can be made to spin on its tip like a spinning top by holding the pin (with head facing up) between thumb and forefinger and rapidly spinning and releasing it in one fluid motion. Push pins can be loaded directly into the breech of a Tippmann 98 Custom paintball gun and fired as projectiles. A flying pushpin rapidly loses stability after a few feet due to poor aerodynamics. Thumbtacks are used as a weapon in professional wrestling. Thumbtacks can cause damage if they are pushed into the skin of any living creature. Thumbtacks should not be swallowed.
