To measure the length of a Case XX pocket knife, lay the knife on a flat surface with its blade out, position a ruler or measuring tape at the butt of the knife, and measure to the tip. For the knife’s closed measurement, repeat the process with the knife closed.
To measure the length of the knife’s blade, measure from the area where the handle and the blade meet. Because some styles of Case XX knives have slanted handles, measure the blade from the lowest possible point on the knife. When measuring knife blades, the American Knife and Tool Institute advises measuring from where the knife’s handle ends to the knife’s tip, and a Texas appellate court ruled that a knife blade includes both the unsharpened and sharpened parts of the blade above the handle of the knife.