i have seen one made on a lathe... two turned pieces with a hole thru both for a long bolt, in one end of the two there was a male and female "punch" to cut/stamp the hole.. (and a valve spring in the female to pust out the stamped out piece) turn them both 180 deg and re-insert the bolt and they would fit together to form the edges of the hole.... could be worked with either a wrench or pneumatic/electric impact wherch....
google time found this:
http://www.mittlerbros.com/punch__flares.htm