The magnets you're referring to are called "neodymium magnets" ... or
"rare earth magnets". Neodymium is a 'rare earth' element. The term
'rare earth' was used many years ago when such metals were in fact rare.

Neodymium is, as one reader noted, very fragile. If you break the
magnets, you'll get sharp splinters. Be careful.

Personally, I would say just buy them! They're fairly inexpensive and
you can more easily find the exact size and shape you're looking for.

Jack

Jay Pique wrote:
Are there usable magnets in old computers that might be good for making
things in a woodshop - like magnetic featherboards? And if so, are
they worth the trouble of getting them out?

JP