On: Repairing a dented tuba with magnets

[zck]

That reverse hammer is fascinating. I'm a little confused by the diagram, though -- I think the magnet stays on the instrument's surface for the entire motion. It never comes away from the instrument, even after the hammerhead hits the stopper.

[fr0sty → zck]

It is called a slide hammer. The blow to the end of the shaft is transferred to the magnet on the opposite end and pulls the magnet inside.