I bought these drills to drill holes in 1/8 inch stained glass windows. Learn how to use them without burning out the diamond coating or breaking the tips. I left a negative review first and hope it didn't last long enough to do any harm. I think I've finally learned how to use them through a lot of trial and error. even more mistakes. Whichever method you use, always remember that these are really thin and fragile pieces and won't take a lot of abuse. I've had terrible luck using these bits with a Dremel and a drill press. The instructions I've read say to drill glass at very low RPM and keep the drill bit (hence the drill press) straight. Dam with spatula plumber. I started making holes at an angle. With the drill in hand, I can barely and gently move the drill, just enough to ream the sides of the hole. I was lucky enough to hold the dremel just long enough to "almost" put my own weight to work. I fill the water inlet with a straw by dipping it in a jar containing just a drop or two of dish soap mixed with water. how i did it