A clinch fastener mechanism including a pivoting base configured to be pivotally connected to a pneumatic fastener tool. The clinch fastener mechanism further includes a clinch arm pivotally connected to the pivoting base at a proximal end of the clinch arm; and a clinch plate disposed on a distal end of the clinch arm, wherein tool operates within three pressure zones. The system may also include a two-valve system which works by moving pressure throughout three specific zones. The first pressure zone has pressure introduced to it by the user attaching the tool to a pressure delivery source, such as a compressor, or other source. The second pressure zone may be used to operate the clinch arm or a safety mechanism. Mechanical safeties may be configured to prevent accidental or double firing of the tool.