I have several drill bits of various sizes and types (all Bosch) and also about 100 or more drill bits of many types and sizes. So I figured I had what it takes to poke holes in whatever I need. Until I had to drill some holes in the sheet metal of my pole shed. The challenge was making smooth holes in the sheet metal walls so I could insert grommets and run cables through them. I used to drill holes in sheet metal, but always with a backing or with the metal between pieces of wood. I found that when trying to drill into cantilevered sheet metal, a conventional drill just leaves a ragged hole - not good! Then I found this step drill that did exactly what I needed: drill smooth holes in unsupported sheet metal. Great find and this piece worked great for it! It may seem like I'll never have all the tools I need, but it's actually fun to discover and acquire.