On one end also a right-handed, and on the other a left-handed, screw-thread is turned.
A new vent can be readily put in, after getting out the old one, without injury to the screw-thread.
The screw-thread is then to be cleaned out, and the new vent-plug screwed in.
It is provided with a screw-thread, by means of which its length, projecting downwards, is regulated.
In the same manner I close the screw-thread hole in gas tubes used for conducting steam.
The fracture usually took place just at the point where the screw-thread terminated.
When we adopt a standard for screw-threads, a screw-thread is adopted which has a manifest advantage.