Sack (unit)

[3] The coal sack was standardized as an imperial hundredweight of 112 avoirdupois pounds, approximately 51 kilograms.

These sacks were large and heavy, weighing at least sixteen pounds when empty, and costing 11 shillings and sixpence before the First World War.

In the American oil industry, a sack represents the amount of portland cement that occupies 1.15 cubic feet (8.6 US gal; 33 L), and in most cases weighs 94 pounds (43 kg).

[9] It has also been used as a measure of volume for dry goods in Britain, with one sack being equivalent to 15 imperial gallons (68 L).

[10] In British usage, a sack of flour was equivalent to 20 stone, 280 pounds (127 kg) or one-eighth of a long ton.