The other yard that I used to work for would only buy aluminum cans uncrushed. The reason for that was: certain people would put a pebble in each can before they crushed them,and when we threw the bags of cans into the smelter,we were left with a little pile of gravel in the bottom of the firing chamber. Each garbage bag of cans should weigh give or take 7 lbs. If they weighed anymore we would not buy them.