Abstract: A fastening system is provided for fastening a plate having open-ended slots formed about its periphery to a supporting wall. The system includes a mounting block which is mounted to the supporting wall, a clevis pivoted on the mounting block, the clevis having a main body portion and two legs extending in the same direction from opposite sides of the main body portion with an elongated opening formed in each leg, a roll pin which extends through the elongated openings and into openings formed on opposite sides of the mounting block, and a slotted binder head machine screw which extends into an opening formed in the main body portion of the clevis and which cooperates with the U-shaped slots formed in the plate. The plate fastening system may further include a compressible gasket interposed between the underside of the plate and the supporting wall.