A self-adjusting clamp system having an upper clamp arm connected to an upper handle and a lower clamp arm connected to a lower handle. The lower handle includes a hollow interior that defines an axis of reciprocation. A wedge lock and activator wedge are positioned within the hollow interior and separated by a separation plate. As the upper handle and lower handle are opened and closed, the wedge lock and activator wedge slide within the hollow interior of the lower handle along the axis of reciprocation as the separation plate slides vertically within a slot in the lower handle. The wedge lock, separation plate and activator wedge work in cooperation with one another to lock and unlock the clamp arms on workpieces of various widths automatically and without user-applied adjustments.