The ton is a unit of measure. It has a long history and has acquired a number of meanings and uses over the years. It is used principally as a unit of weight, and as a unit of volume. It can also be used as a measure of energy, for truck classification, or as a colloquial term.

It is derived from the tun, the term applied to a barrel of the largest size. This could contain a volume between 210 and 256 gallons (800 to 1000 L), which could weigh around 2,000 pounds (900 kg) and occupy some 60 cubic feet (1.7 m3) of space.

In the United Kingdom the ton is defined as 2,240 pounds (1,016 kg) (avoirdupois pounds). From 1965 the UK embarked upon a programme of metrication and gradually introduced metric units, including the tonne (metric ton), a non-SI metric unit defined as 1000 kg. The UK Weights and Measures Act 1985 explicitly excluded from use for trade many units and terms, including the ton and the term "metric ton" for "tonne"

In the United States and Canada a ton is defined to be 2,000 pounds (907 kg).

Where confusion is possible, the 2240 lb ton is called "long ton" and the 2000 lb ton "short ton"; the tonne is distinguished by its spelling, but usually pronounced the same as ton, hence the US term "metric ton". In the UK the final "e" of "tonne" can also be pronounced (/ˈtʌnɪ/), or "metric ton" when it is necessary to make the distinction.

Where accuracy is required the correct term must be used, but for many purposes this is not necessary: the metric and long tons differ by only 1.6%, and the short ton is within 11% of both. The ton is the heaviest unit of weight referred to in colloquial speech.

The term "ton" is also used to refer to a number of units of volume, ranging from 35 to 100 cubic feet (0.99 to 2.8 m3) in capacity.

It can also be used as a unit of energy, expressed as an equivalent of coal burnt, TNT detonated, or in refrigeration, ice melted.

In Britain ton is used in slang in several contexts to mean "100". As a cost or a speed, a ton is widely understood to be £100 or 100 mph.

Read more about Ton:  Units of Mass/weight

Other articles related to "ton, tons":

Shoals Marine Laboratory - Research Vessels
... serviced by two research vessels the 47', 34.49 gross ton R/V John M ... Kingsbury and the 35.7', 13 gross ton R/V John B ... Kingsbury has a winch and a one ton crane for the deployment of research equipment and for the movement of heavy materials from the mainland to the island ...
Truck Classification - Ton Rating
... light-duty trucks were first produced, they were rated by their payload capacity in tons (e.g ... ½-, ¾- and 1-ton) ... Therefore, the Ford Ranger, Chevy S-10, and GMC S-15 are called quarter-tons (¼-ton) ...
Petr Ton
... Petr Ton (born 8 October 1973) is Czech ice hockey forward ... In 2006-2007 season Ton played 67 games and scored 36 goals in Czech Extraliga for HC Sparta Praha ... Ton scored 163 goals in Czech Extraliga ...
Sailing At The Summer Olympics - Olympic Classes (equipment)
84 16 ... Sailed Events Boats of the Royal Navy • 0 ½ ton • 1 ½–1 ton • 1 1–2 ton • 1 2–3 ton • 1 3–10 ton • 1 10–20 ton • 1 Open class • 1 ...

Famous quotes containing the word ton:

    A ton of reading does not equal one good teacher.
    Chinese proverb.

    Hearing your words, and not a word among them
    Tuned to my liking, on a salty day
    When inland woods were pushed by winds, that flung them
    Hissing to leeward like a ton of spray,
    Edna St. Vincent Millay (1892–1950)