they appear to me to be too thin for that,unless they used abrasive cutters, like what’s on a chop saw, but not the brute force your describing
Here’s a picture of an old shaper taking off a 2" x 1/32" chip from a piece of steel.
And a video of a fairly large cut, again in steel. http://www.youtube.com/watch?v=YEIzbCD8qWc
Seems easy enough on Copper or Aluminum.
problem isn’t whether it can cut or not, the fins are too thin, and would have been destroyed in the process.
The links providing for the process clearly show it making fins that thin.
The second picture in post #22 shows a copper heat sink being skived. Skiving is also used to make long, continuous ribbons of metal from a large, round blank. I wish I could find a good video of the process.