Convert Ton (Assay) (US) (AT (US)) to Pound-force Square Second/Foot (lbf·s²/ft) instantly.
About these units
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.
Pound-force Square Second/Foot (lbf·s²/ft)
This unit is part of the British Gravitational System, where mass is defined from force rather than the other way around. It can be interpreted as an inertial mass unit, since applying 1 pound-force to it would produce an acceleration of 1 foot per second squared. Historically, before the SI system clarified the distinction between force and mass, engineering fields often used mixed systems where pounds could represent either force (lbf) or mass (lbm). The unit lbf·s²/ft was introduced to straighten out these ambiguities in dynamic calculations such as impact forces, mechanical oscillations, and safety load computations. Today, the unit survives mostly in engineering textbooks, legacy calculations, and historical documentation. It demonstrates how complex and inconsistent measurement systems once were, and why global scientific communities moved toward SI clarity.