I claim the ornamental design for a diamond saw blade, as shown and described.
FIG. 1 is a top plan view of a diamond saw blade showing my new design;
FIG. 2 is a bottom plan view of the diamond saw blade in FIG. 1;
FIG. 3 is an enlarged and partial top perspective view of the diamond saw blade in FIG. 1;
FIG. 4 is an enlarged and partial top perspective view of a single set of teeth of the diamond saw blade in FIG. 1, wherein the area of enlargement is taken at the broken line reference bubble marked 4 in FIG. 3; and,
FIG. 5 is an enlarged and partial side perspective view of the diamond saw blade in FIG. 1, wherein the area of enlargement is taken at the broken line reference bubble marked 5 in FIG. 1.
The broken lines in the drawings illustrate graphical symbols of cutaway areas and reference bubbles for enlargement views. The aforementioned graphical symbols do form part of the claimed design.