| 摘要 |
Process for applying a threaded seat for connecting a closing means or operations means to a metal plate, such as the wall of a drum, by making a hole in the plate and by drawing a cylindrical collar from the periphery around said hole approximately at a right angle to the plane of the plate, whereafter a thread is made in the part drawn from the plane of the plate, wherein a thread is provided in the collar between the plane of the plate and the end edge of the collar. |
