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 ... for larger drill bits, but the ...

Consisting of three cones fitted with steel or tungsten carbide cutting elements that rotate independently as the drill ...

These are robust steel drill bits, good for drilling into wood ... These include titanium and even crushed diamond. For drilling into metals such as stainless steel, your best bet is a HSS ...