FIG. 1 is a front view of the holster for wrenches in accordance with the present design; FIG. 2 is a rear view thereof; FIG. 3 is a right front perspective view thereof; FIG. 4 is a left front perspective view thereof; FIG. 5 is a right side perspective view thereof; FIG. 6 is a left side perspective view thereof; FIG. 7 is a top view thereof; and, FIG. 8 is a bottom view thereof.