| 摘要 |
A threaded fastener has a substantially single helical thread formed upon a shank portion thereof, and a plurality of substantially saw-blade type or serrated teeth are formed upon crest portions of leading ones of individual thread portions of the helical thread. The saw-blade type or serrated teeth cut into side wall portions of any one of a multiplicity of substrates so as to substantially reduce re- quired insertion torque levels, render fastener insertion operations quicker, and enhance fastener pull-out resistance values.
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