Walnut Stair Treads
Black walnut is rarely used for stair treads or other stair parts, because of its darker color. Most home designers like to use lighter colors, because darker colors like walnut usually create depressing environments. However, if you did like the color or wanted to mix it up with other hardwoods, it's hard enough to make a durable stair tread.
Black Walnut usually has a dark brown to a darker
brown color, but can be found with lighter brown to a darker brown, with
a hint of purple. If this hardwood is sanded enough, it can produce an
incredible finish, as a matter of fact, you can usually see your
reflection in highly polished, darker hardwoods. Remember, highly
polished stair treads are slippery and should have some sort of non-slip
materials, running through them, to prevent any personal injuries.
Gluing = Great, Walnut might not be the best wood to glue, but it will definitely hold together, if glued properly.
Sanding = Good, Walnut can be sanded, even though it's not one of the softer hardwoods. However, like I said earlier, this particular wood can be sanded, polished and then finished, to a mirror like perfection.
Staining = Poor, You could try and stain it, but your efforts might prove to be futile, because they might not sell any stains dark enough, to make a big difference.
Nailing = Good, you shouldn't have a problem nailing or screwing into walnut, but every once in awhile you're going to hit a spot that's going to be difficult. Even though some of the hardwoods are harder than others, it wouldn't be a bad idea to pre-drill any holes, in areas that you can't afford to damage.
Wear And Tear = Excellent, about 20 years ago I was looking through a magazine that had an old picture of a stairway that was built out of walnut. It was actually located in a home that was over 150 years old. The stairway still looked like it was in great shape, but with a little tender loving care, it would have looked fantastic.
Janka Hardness Scale = 1010