Abstract: An adjustable wrench comprising a handle, a stationary outer jaw member integrally formed with the handle and having at least one outer face and a support surface for a moveable jaw, and a moveable jaw member riding on the support surface and continuously supported thereby during its entire range of movement, the moveable jaw member having an inner face parallel to the stationary outer face whereby the turning of a nut placed between the stationary outer face and the moveable inner face creates a force a part of which is applied to the moveable jaw member in a direction perpendicular to the direction of travel of the moveable jaw member thereby forcing the moveable jaw member against the support surface.