It really depends on how corse the shavings are, if you do any work to compress the metal shavings, and the density of the alloy. However I think you're right, because 53lb of steel is only about 0.1ft^3.
I assure you it isn't. I've lifted them many times. I'd say 75-100lbs is normal, depending on the distribution of metals (obviously steel is heavier than aluminum for example).