Convert Ton (Assay) (UK) (AT (UK)) to Stone (US) (st (US)) instantly.
About these units
Ton (Assay) (UK) (AT (UK))
The UK assay ton, slightly different from the US version, is defined as 32.666 grams. Like its American counterpart, it was designed so that milligram-level assay results could be easily interpreted as ounces of metal per ton of ore. In British mining operations of the 19th and early 20th centuries, the UK assay ton streamlined economic decision-making by directly correlating lab-scale measurements with bulk extraction expectations. Although now historical, its existence illustrates how different countries tailored their measurement systems to local mining economics and metal markets.
Stone (US) (st (US))
The US stone was an informal and nonstandardized unit occasionally used in the 19th century, with no single agreed-upon value. Unlike the British stone (14 pounds), the US stone varied regionally and by trade context, typically ranging from 12 to 16 pounds, depending on the commodity and location. Farmers, butchers, and merchants sometimes used stones to weigh produce, meat, or livestock, but the lack of uniform regulation prevented it from becoming an official or widely adopted unit. Today, the US stone is entirely obsolete, but references to it appear in historical American trade documents, agricultural records, and pre-standardization weight systems. It serves as a reminder of the diversity of early American measurements before the widespread adoption of the avoirdupois pound.