External thread cutting.
<video controls autoplay loop> <source src="https://s3-us-west-1.amazonaws.com/hmt-forum/threaded_shaft_cutting_chasing.mp4" type="video/mp4"> Your browser does not support the video tag. </video>
Previously:
https://www.homemadetools.net/forum/...931#post175666
https://www.homemadetools.net/forum/...855#post175335
https://www.homemadetools.net/forum/...867#post152552
https://www.homemadetools.net/forum/...3730#post99885
https://www.homemadetools.net/forum/...7894#post86435