SHEET METAL FASTENING SYSTEM
Original Publication Date: 1997-Oct-31
Included in the Prior Art Database: 2004-Apr-08
Xerox Disclosure Journal
There is provided a method for joining together two sheets of metal, which is an improvement over the well-known nut-and-bolt method. First and second sheets of metal have a hole drilled through them at the required joining position. A conical indent is punched into the second sheet centred around the drill hole. In the joining operation, the drill holes on the metal sheets are aligned, with the conically indented part of the second metal sheet facing the first metal sheet. A conventional bolt is then in inserted through the first hole and into the conical indentation. Torque is applied to the bolt which thereby, cuts a thread pattern into the conical sides of the indent. As further torque is applied to the bolt, its thread draws the sides of the conical indent radially inward, closing the inside diameter of the hole in the second metal sheet around the threaded parts of the bolt.