The unique feature of this patent is the adjustment lock. A portion of the pin the adjusting worm rides on is enlarged. One end extends beyond the frame of the wrench where it has a knob. The other end is threaded into the wrench frame, and peened over so it cannot be removed. Screwing the pin in causes the adjusting worm to jam in the frame. The wrench was produced in both nut wrench and pipe wrench versions.