Adjustable wrench

An adjustable wrench comprising:

• a body used to operate the adjustable wrench and including a fixed jaw extending outward therefrom and having a polygonal first engaging surface formed on a lower side of the fixed jaw, and the fixed jaw also having a holder mounted on a top end thereof, the body further including an arcuate recess with an inlet and an outlet fixed on a middle portion of a front side thereof and with a notch proximate to the outlet, and including a cavity adjacent to the notch;
• a movable jaw pivoted in the holder and including a polygonal second engaging surface formed on an inner wall thereof in response to the first engaging surface so as to engage a workpiece, including a guiding rib relative to the arcuate recess extending from a bottom end thereof to be adjusted and moved along the arcuate recess;
• a locking mechanism axially displacing in the cavity of the body and including a control unit to operate the locking mechanism and to drive a pushing member, the control unit being an axial mount and including locking and unlocking positions so as to move the pushing member across the notch of the arcuate recess and then to bias against the guiding rib, thereafter, the pushing member is driven to move downward, thus disengaging the guiding rib to slide freely.