1. A TOOL HOLDER COMPRISING A SOCKET HAVING AN OUTWARDLY FLARING OUTER END, A SHANK EXTENDING LONGITUDINALLY OF THE SOCKET, A HEAD ON THE SHANK NEAR THE OPENING OF THE SOCKET AND HAVING A WORKING SURFACE FACING INTO THE SOCKET, A PAIR OF OPPOSED GRIPPING JAWS HAVING INNER ENDS ENCLOSING SAID HEAD AND SHAPED SLIDABLY TO FIT IN THE SOCKET, SECURING MEANS ON THE INNER ENDS OF THE JAWS REMOVABLY ENGAGING SAID WORKING SURFACE, CAM SURFACES ON THE INNER ENDS OF THE JAWS, A PRESSURE PLATE SLIDABLY MOUNTED ON THE SHANK, RESILIENT PRESSURE MEANS URGING THE PRESSURE PLATE AGAINST THE JAW CAM SURFACES TO PRESS THE JAW SECURING MEANS AGAINST THE SHANK HEAD THEREBY