A convertible clamp device including a C-shaped frame having first and second substantially opposing interconnected arms; a clamping rod carried by the first arm for longitudinal movement in a first clamping direction toward an internal face of the second arm and in a second opposite direction away from the second arm; different first and second movable clamping jaws removably coupleable to a portion of the clamping rod between the arms of the frame; and different first and second stationary clamping anvils being disposable on the internal face of the second arm.