Abstract: A wrench capable of being quickly adjusted and secured in position by the sliding movement and wedging action of the movable parts of the wrench. The wrench comprises a handle portion and a head portion provided with a fixed jaw, a movable jaw carried by the head portion having an angled bottom surface, a slot formed in the head portion with a surface portion disposed in a plane oblique to the direction of movement of the movable jaw, a movable cleat carried within the slot, a guide channel formed in the head portion for slidably receiving the movable jaw, and a set of gripping plates affixed laterally to the cleat. Movement of the gripping plates cooperatively moves the cleat which in turn engages and cooperatively moves the movable jaw until the jaw secures the nut or bolt against the fixed jaw.