| 摘要 |
<p>A metal plug (10) has a cone section (16) with an external thread (18). A metal coupling (12) has a cone cavity (20) with an internal thread (22) that interconnects with the external thread of the plug. A guide pin (24) on the front end of the plug is insertable into a center hole (26) in the cone cavity of the coupling. The guide pin has parallel and opposing flattenings (28) separated by an appropriate distance corresponding to a specific wrench width. An independent claim is also included for a coupling.</p> |
