A time comes in every maker’s life when he just has to drill through steel. Sure, you could use heat to soften it up first, but that would weaken the entire piece of metal. Instead, you need a little trick called spot annealing.

For the latest episode in the Rebuild video series, Popular Science columnist Chris Hackett needed to punch a hole through a razor blade so he could fasten it to a handle and wield it as a knife. Using spot annealing, Hackett drilled a hole through the metal without damaging its cutting edge–or destroying his drill bit.

Learn more tips and tactics from Hackett in his new book, Maker Skills.