So, found out the hard way that you can’t apply heat to neodymium magnets. Had 16 magnets to press into a print (tool holder). Thought since the soldering pen I use for inserting threaded nuts into prints works so well, I would use it for this too. And it did work well, but now all the magnets are not magnets any more. Yup, heat will demagnetize them. Part is useless, so had to trash it. Found out something new, but wish I had heard about this beforehand.
I just stack the magnets first to get them all in the same polarity, and insert them, using the stack to push it into the hole, with a press fit they won’t jump out