| 摘要 |
A blind fastener comprises a bolt having an externally threaded shank, a head at one end of the shank, a pair of opposed flat wrenching surfaces at the other end of the shank, an annular breaker groove in the shank intermediate the head and the wrenching surfaces, and four swaging grooves in the shank intermediate the said breaker groove and the bolt head. A tubular nut is in threaded engagement with the shank of the bolt, the nut having an enlarged hexagonal head at the end thereof remote from the head of the bolt. The fastener also comprises an expandable tubular member on the shank of the bolt between the head of the bolt and the nut. A locking ring is positioned around the bolt shank at a position thereon on the side of the nut head remote from the bolt head, the locking member being swageable, after the nut and bolt have been screwed towards each other thereby to expand the expandable member to form a blind head, into at least one of the swaging grooves in the shank, thereby to lock the nut and bolt together.
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