In old cartoons (Looney tunes, Tom and Jerry, etc), should anything fall on a character, most of the time it's an anvil. Why the anvil specifically? Did the kids understand what it was despite blacksmith's being less and less common?

by Sillvaro

Obviously, by the time of those old cartoons, specifically from the 40's to the 60's (and even more true through the 70's and 80's), the job of Blacksmith was becoming less and less useful in urban areas, where kids who could watch television lived. Why then use an anvil for the gags where a character gets hit on the head with a heavy object? Did the kids understand what it was? If not, why use this object?