It is not to be confused with the short ton, a unit of weight equal to 2,000 pounds (907.2 kg) used in the United States, and Canada before metrication, also referred to simply as a "ton".
The long ton arises from the traditional British measurement system: A long ton is 20 long hundredweight (cwt), each of which is 8 stone (1 stone = 14 pounds).
[5] In the United States, the long ton is commonly used in measuring the displacement of ships and the shipping of baled commodities[1] and bulk goods like iron ore and elemental sulfur.
[citation needed] The long ton was the unit prescribed for warships by the Washington Naval Treaty of 1922; for example, battleships were limited to a displacement of 35,000 long tons (35,560 t; 39,200 short tons).
The long ton is traditionally used as the unit of weight in international contracts for many bulk goods and commodities.