Fastener for Corrugated Sheet

A fastener for a corrugated sheet comprising:

• a cylindrical assembly including a plurality of elongated, plate shaped fastening members assembled as a hollow cylinder, each fastening member tapered to one end to form a hook at one end and having a curved groove on an outer surface, and a curved trough on the outer surface at the other end of the fastening member, the curved troughs assembled to form an annular recess;
• a retainer ring secured to the annular recess and having an opening at one end;
• a ring-shaped elastic member secured to the curved groove;
• a first sealing member put on a peripheral surface of the retainer ring;
• and a washer;
• a threaded bolt driven through the washer, the retainer ring, and the fastening members to have an open end proximate to the hooks;
• and
• an expansion nut having a multi-sided outer surface and moveably secured to the threaded bolt, the expansion nut being surrounded by the hooks.