Go pound sand

'Go pound sand' is a uniquely American expression that dates from the early 19th century, and means much the same thing as 'go jump in the lake' or 'get lost'. The origin stems from the iron foundry process where sand, mixed with water and clay, was used to form moulds into which molten iron was poured to make things like cannonballs, pots, and pans etc. Pounding clay and water into sand was hard work and was generally a punishment chore given to worlers who stepped out of line for any reason. The works foreman would typically yell at miscreant workers, "You two, go pound sand!" By the early 19th century, 'go pound sand' had become colloquial in parts of the northern US states, where to 'go pound sand' meant to 'go away' as a euphemism for 'go to hell'. 'Go pound sand' is unique in the sense that it has not been adopted anywhere else in the English-speaking world.