I claim the ornamental design for a tool rack, as shown and described.
FIG. 1 is a perspective view of a tool rack, showing my new design;
FIG. 2 is a front view of the tool rack shown in FIG. 1;
FIG. 3 is a rear view of the tool rack shown in FIG. 1, wherein several cavities are shown in broken lines for illustrative purposes only and do not form part of the claimed design;
FIG. 4 is a left side view of the tool rack shown in FIG. 1
FIG. 5 is a right side view of the tool rack shown in FIG. 1;
FIG. 6 is a top view of the tool rack shown in FIG. 1;
FIG. 7 is a bottom view of the tool rack shown in FIG. 1; and,
FIG. 8 is another perspective view of the tool rack of FIG. 1, wherein wrenches are shown in broken lines for illustrative purposes only and do not form part of the claimed design.