Ah, but an American cwt is still 100lb, rather than 112lb. So, although there are always 20 cwt in a ton, an American ton is only 2,000lb and an Imperial ton is 2,240lb. Sometimes these are referred to as a short ton and a long ton, if you want to confuse the issue further. Then there's a metric tonne, which is 1,000kg, or about 2,205lb.