A long time ago in my youth, I worked at a wood working machine shop where we would occasionally run walnut lumber through a ripsaw and other machines. The stuff would produce clouds of *very* irritating smoke, and it seemed to dull the saw blades a lot faster than the other hardwoods. It's not an easy wood to work with. The finished product in a piece of furniture is very nice looking though. As I recall, the walnut lumber cost more than any of the other woods we had available.