These things are incredible. They save time! Drill, tap, and deburr in one operation. One-piece drill/tap guarantees correct drill for tap size. Tapered design prevents thread damage from over drilling. They are great for mounting sheet metal to tabs, just drill the hole were you want it and bolt your panel on. No more lining up the Drill then taping the hold and making the sheet hopeful that it will all line up. These are made of high-speed steel for long life.