[Bob Steele]

Depending on the strength of the magnet you may not be able to drill through it. Your biggest problem is probably the hardness of the magnet compared with the drill you are using but there are other complications.

The reason this is the case is because the chips that normally would be falling away as you drill are actually attracted to each other and stay in the "hole" They won't leave an empty spot...
So you can't drill.

The holes you see in Neodymium magnets are actually placed there during the manufacture of the magnet.... usually during a compression like activity that forms the magnet.... About the only other way a hole could be made is by an enormously hard and strong punch press....and even then it is extremely difficult...

Weak magnets "might" be able to have a hole drilled in them...but strong magnets will only cause you grief.

It would be like digging a hole in the ground but not being able to take any dirt out of the hole....your shovel would continue to try over and over to remove the same dirt.... it would overheat.... and eventually melt....

Well at least in the case of a drill bit that is what will happen. The heat has to go somewhere and the bit heats...distempers.... turns blue and is wasted...

Also remember that the magnet may well be harder than your blades or bits.... if its not harder it can't cut anyway...

Does that make any sense to you?