Lasco"s 1/8" Diamond Coated Core Drill works great for drilling 3.5mm holes in stone, glass, wood, tile, metal, and more. It has a 1/8" Steel Shank. It is coated in 100% natural diamond and made in the USA. It works best on a drill press, but may also be used by hand in a Dremel, Foredom, or similar drill that will chuck a 1/8" Shank.