Abstract: A parallel, slidable and lockable jaw wrench is disclosed with an over-center locking handle mechanism. The parallel, slidable and lockable jaw wrench has different interchangeable head assemblies adaptable for locking different types of objects depending on the particular head assembly used. Each respective interchangeable head assembly has a horizontally slidable first jaw with a working surface that is adjacent to a working surface of a fixed second jaw that extends from the handle. The slidable first jaw utilizes a plurality of ball bearings disposed within a channel to slide toward and away from the fixed second jaw smoothly. Also, the slidable jaw locks in any spaced apart distance from the first fixed jaw.