| 摘要 |
A method of forming a sheet metal part including a nut structure by providing a sheet of metal, forming a tubular structure projecting integrally from the main body of the sheet, and tapping the tubular structure to form an internal screw thread within the tubular structure. The method is carried out on a press having a plurality of spaced stations including a punch station and a working station. The tubular structure is formed by punching a hole in the sheet at the punch station and thereafter forming the tubular structure in surrounding relation to the hole in a single hit of the press at the working station. The hole is punched in the sheet utilizing a punch and die wherein the diameter of the die is no greater than approximately five percent greater than the diameter of the punch whereby to provide a hole having a cleanly cut sidewall and thereby preclude splitting of the metal of the sheet as the tubular structure is formed at the working station. A coin formation is also formed in the single hit of the press at the working station to accommodate the head of an associated threaded plug adapted to be threaded into the internally threaded tubular structure.
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