1. A SELF-LOCKING CLAMP COMPRISING A FIXED JAW MEMBER AND A MOVABLE JAW MEMBER, A THREADED MEMBER EXTENDING THROUGH SAID MOVABLE JAW AND SECURED AGAINST LINEAR MOVEMENT RELATIVE THERETO AND THREADEDLY ENGAGING THROUGH MEANS CARRIED BY SAID FIXED JAW WHEREBY ROTATIVE MOVEMENT OF SAID SCREW MOVES SAID MOVABLE JAW RELATIVE TO SAID FIXED JAW, A KNOB ON THE END OF SAID SCREW WHICH EXTENDS THROUGH SAID MOVABLE JAW, A TOOTHED DISC FIXED TO SAID MOVABLE JAW BETWEEN SAID MOVABLE JAW AND SAID KNOB AND SURROUNDING SAID SCREW, AND A FINGER PIVOTED ON SAID KNOB SELECTIVELY MOVABLE INTO AND OUT OF ENGAGEMENT WITH THE TEETH OF SAID DISC TO PRECLUDE ROTATION OF SAID KNOB AND SAID SCREW WHEN ENGAGED WITH SAID TEETH.