With adequate lubrication in a drill press, carbide-tipped hole saws can drill through metal that is up to 5/8" thick. Though it’s possible to use a hole saw with a hand-held drill to bore a ...

It turns out that a hot solution of alum (ammonium aluminum sulfate), which is available in the spice rack of your local supermarket, will dissolve the steel drill bit without reacting with the brass.

So it’s always a joy to pick up a new trick, especially one as simple as putting a hardened edge on mild steel using a drill bit as a filler rod. This tip comes to us by way of [Jody], aka ...