An end effector for a surgical tool includes a first jaw that defines an aperture, a second jaw rotatably coupled to the first jaw, and a spacer pin received within the aperture and protruding from an upper surface of the first jaw. The spacer pin is adjustable within the aperture to define a jaw gap between the first and second jaws when the second jaw is moved to a closed position and engages the spacer pin, and the spacer pin is secured within the aperture to set the jaw gap.