Abstract: An adjustable wrench and method for loosening or tightening a fastener includes a handle member having a fixed jaw segment, a substantially transverse channel therethrough, and a void in communication with the channel. Also, a movable jaw member having a serrated toothed rack that is slidably engaged within the channel. In addition, a beam that is slidably engaged within the void, the beam including a toothed rack that selectably matably engages with the movable jaw toothed rack to help secure the jaw in position. Finally, included is a trigger member that is pivotally attached to the movable jaw member and is slidably engaged with the handle member, the trigger facilitates manual movement of the movable jaw from the closed state to the open state and vice versa, when the movable jaw toothed rack and the beam toothed rack are selectively disengaged.