The lowest of the four individual elements is the final grade that allocated to the meat.
The combination of A to C and 1 to 5 grades make clear identification of Wagyu grades.
The majority of Wagyu exported from Japan is generally awarded the highest grade of 5 or 4 in meat quality and meat of such level is atypical even in Japan.
The yield grade indicates the amount of primal cut meat retrieved from the cattle and, based on the fact that exported beef is primal cuts.
Thus, there is no difference in the actual meat quality of A5 and B5.