Abstract: A tool for clamping a workpiece on a table or comparable support while work is being performed on the workpiece has a pair of elongated arms, one below the table and the other, when in use, above the table. The vertically spaced arms are swingable in horizontal planes about spaced, vertical axes, the axis of swinging movement of the lower arm being beneath the table. An upright post secured to the lower arm in spaced relationship to the table, and extending upwardly from the lower arm, swingably supports one end of the upper arm. A screw carried above the table by the upper arm at its opposite end is movable downwardly to a position clamping the workpiece onto the upper surface of the table.