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.
This should be higher up. OP clearly learned a lesson here but one larger lesson most everyone can learn is that neodymium magnets aren’t the only kind of magnets. Especially when high temperature performance is needed. Samarium Cobalt magnets are much better suited for high temperature and corrosive applications. Plus if I remember correctly they’ve been around longer.
Most neodymium loses it’s magnetism at 200-230C. Some Samarium Cobalt can retain their magnetic properties all the way up to 350C or higher grades up to 500C (1022F)
I nerded out on this a few years ago when I made a magnetic thermal blanket for my pellet smoker and experienced the same thing. Samarium Cobalt did the trick in my application.