Metal Magic: Using Reamers For Accurate Holes - Kitplanes Magazine Watch in HD on YouTube! Share on Facebook! Sometimes a drill bit just won't do. When you want accurate, perfectly round holes in aluminum, you need to use a reamer. KITPLANES editor at large Paul Dye discusses when you want to use a reamer, and how to use one in this episode of Metal Magic, sponsored by Aircraft Spruce & Specialty.