| 摘要 |
<p>The dowel is cylindrical and hollow, its bottom end having a conical portion which will produce a tighter grip in the hole at the base. The outside end of the plug has a serrations which prevent the dowel from slipping in the hole at the outer end. The plug is split by a groove over most of its length to allow the passage of the screw. An insert is lodged above the outer serration within the dowel. The inside of the plug is tapped to take the woodscrew.</p> |
