| 摘要 |
An improved screw head nail includes a cylindrical machine screw and a nail having an upper end defining a nail head, a lower end defining a nail point, and a nail shank disposed therebetween. The nail shank has a centrally disposed threaded cylindrical bore extending from the nail head towards the nail point. The nail head has a generally frustoconical opening formed therethrough which is aligned with and opens onto the cylindrical bore and which, upon flattening of the nail head, protects the cylindrical bore from substantial damage and exposes the same for allowing full threaded receipt of the machine screw therein.
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