These nuts are very useful. They contain the highest protein content of any tree nut. Black walnut shells were used to clean the Statue of Liberty. The US Navy has used Black Walnut shells to clean Navy ships and submarines. Black Walnut shells are used as a filler in dynamite. These nuts are also used to make ink.
It is not recommended to park near or under balck walnut trees in the fall, because the heavy, big nuts can dent car exteriors and send you to an emergency room.