Convert UK Ton (Long) (ton (UK)) to Ton (Assay) (US) (AT (US)) instantly.
About these units
UK Ton (Long) (ton (UK))
The British long ton equals 2,240 pounds (1,016.0469088 kilograms). Historically used throughout the British Empire, it appears frequently in naval records, early engineering documents, and historical trade ledgers. The long ton's relation to the imperial hundredweight (112 pounds × 20) makes sense within the structure of older English measurement systems. Although replaced by metric tons in the UK, it persists in maritime contexts and in interpreting historical documents. Its presence captures the complexity of pre-metric trade and the need for careful interpretation when comparing international tonnage systems.
Ton (Assay) (US) (AT (US))
The US assay ton is a specialized unit used in mining and metallurgy for evaluating ore grades. It is defined as 29.166⅔ grams, a very small mass chosen to simplify calculations relating assay results to tons of ore. The idea is that if an assay ton of sample yields 1 milligram of precious metal, then one actual ton of ore contains 1 ounce of that metal. This scaling makes laboratory results directly translatable to mining yields. While obsolete in modern industrial practice, where metric units dominate, the assay ton remains important in historical mining records and for researchers studying early industrial metallurgy.