Mallet head metal

In a game were a almost all the mallets are made by the user, you can't expect everyone's mallet to be perfect.

I don't care whether the mallet is perfect from the point of balance, looks and geometry. All I care about potential dangers to players.

Everyone should be able to make a mallet using the nut & bolt method by now. The pics showing how to do it have been posted all over the place, and it's so simple that even I can do it.