A threaded fastener has a casing enclosing at least three radially inwardly biased arcuate segments positioned to engage {HEAD ~ the threads} of a bolt or {TAIL ~ hollow threaded member} 
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A threaded fastener has a casing enclosing at least three radially inwardly biased arcuate segments positioned to engage { HEAD ~ the threads } of a bolt or { TAIL ~ hollow threaded member }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL