The wrench comprises a body that includes a handle that supports a fixed jaw. The body further includes a passage for receiving a movable jaw. A movable jaw includes an engagement portion that is slidably received in the passage such that the movable jaw is able to slide in the passage relative to the fixed jaw. The movable jaw includes a series of ratchet teeth. The ratchet teeth are arranged such that the distal ends of the teeth are in a plane where the plane is at an oblique angle with respect to the direction of movement of the movable jaw. The engagement faces of the teeth are perpendicular to the plane. A ratcheting locking mechanism is provided that prevents movement of the jaws away from one another but allows movement of the jaws towards one another.