A jaw assembly for a clamp is provided that comprises a jaw body having a jaw rotatably mounted on the jaw body. A locking member is movable between a first position where the jaw is locked relative to the jaw body and a second position where the jaw is unlocked relative to the jaw body such that it can rotate relative thereto. A clamp is also provided that incorporates the jaw assembly. In the unlocked position the jaw can pivot such that it can orient itself relative to the workpiece and in the locked position the jaw is fixed such that it can clamp the edges of a workpiece. A method of operating a clamp is also set forth.