| 摘要 |
<p>1380857 Screws and method of fitting ITT INDUSTRIES Inc 19 April 1973 [4 May 1972] 18914/73 Heading B3N To facilitate the fitting of a self-tapping screw 1, particularly a plastics screw, into a body 4 of plastics material having a hole 5, the hole has a groove or grooves 6 of a depth substantially equal to the height of the screw thread to provide a discharge duct or ducts for plastics material removed by the screw. The grooves may be spiral.</p> |
