| 摘要 |
In a preferred embodiment, a metal nut compacted and welded within the thickness of a metal sheet, within a sheet-aperture of lesser diameter than a top of the nut, spaced-apart compacted edge portions of the nut's top having a larger diameter than the nut's top at other edge locations in the compacted state, and the sheet's malleable metal of bottom portions thereof adjacent the aperture being compacted against and welded to malleable metal of a circumscribing side wall of the nut.
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