AT its best, an adz is a rather dangerous tool to use, and to have it work loose is nearly certain to end in disaster. A tightener as shown here is not expensive, can be put on any adz, and will last as Jong as the adz itself. On the upper edge of the head drill a hole and tap for a %-inch set-screw as Adz-tightener. shown in the drawing. Have the square head on the set-screw flattened like a thumb screw, so that you can tighten or loosen it with the claws of your hammer. Next, make a thin strip of iron the width and length of the upper side of the eye. The set-screw bears on this iron strip and makes the pressure 011 the handle even.