are there different grades of walnut(flooring vs furniture)

I understand grading walnut for knots or grain patterns.
I choose my walnut off of 20 pallets of walnut in all thicknesses and lengths up to 48 inches.
The pallets were bought out for flooring.
The buyer told me he would use some of the very wide pieces (nice swirly grain patterns)to build tops for tables or whatever, but Im finding the walnut I purchased from him to be a bit on the touchy side.
Splintering easily, almost as if its a bit brittle? Ive never worked with walnut, so I have zero experience, but are there different grades of this hardwood for flooring purposes vs. furniture grade? If so, how do I tell the difference?

As far as I know flooring is graded by #1 being clear and free of knots, #2 has knots but they are tight with no viods and #3 has loose knots, knot holes and splits. I dont tink it would be graded differently just that a board that would be a lower grade for furniture making because of knots and splits could yield #1 material for flooring because of being cut into smaller pieces.

I agree with alan B opinion on the grading. As for the splintering and brittle, perhaps it is a bit too dry, never had that problem in all my years of working with Walnut (American Black Walnut) usually it never splinters as the grain is short and dense, are you sure you have American Black Walnut? It does shear and fracture easily but not much splintering... IMHO