Abstract: A mounting and fastening device for electronic printed circuit boards (PCBs) in a rack of an electronic enclosure. In particular, the assembly uses an elongated clamping assembly with or without a torque limiting clutching device that may form part of the torque tightening component of the device. The fastening assembly expands transversely to fasten the PCB and maintains a proper thermal conductive path between enclosure and PCB. The expandable clamping feature of the invention has several embodiments.