Porta-Vise PVF Series Bar Clamps (Closeout) Porta-Vise PVF series clamp incorporates the patented Porta-Vise non-rotating shaft and pad into a sliding bar clamp for quick clamping. Hex handle allows for use with a socket or wrench for speed and power. Non-rotating shaft and pad for precision placement without deflection, copper plated to resist weld spatter. Made in USA.