Convert Stone (st) to Ton (Assay) (US) (AT (US)) instantly.
About these units
Stone (st)
The stone equals 14 pounds, or approximately 6.35029 kilograms, and is commonly used in the United Kingdom and Ireland for expressing human body weight. It has deep traditional roots, originating from stones used as counterweights in early commerce. Although largely replaced by metric units in most applications, the stone remains emotionally and culturally significant for personal weight expression in the UK. Many people find it more intuitive and relatable than kilograms due to long-standing social habits. The stone's endurance highlights how measurement systems reflect cultural identity as much as mathematical convenience. It is one of the few units still commonly used in conversation but not in scientific or industrial contexts.
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.