****** - Verified Buyer
4.5
Like all these bits made for very hard material, these wear donw over time. The wax is actually suprisingly helpful and this brand does not wear down as fast as others. I refuse to invest in high end expensive ones because they ultimately wear down too.I use them for drilling holes in ceramic and concrete planters (never come with enough holes IMO), and have done probably 15+ holes with one and can still use it. I also don't mean cheap planters, nice thick ceramic and some very thick cement, even coated ceramic, not a problem.It takes time and patience and a little getting used to, but I can do a hole in a 3/5 inch ceramic planter in less than 10 minutes. If that seems like a lot, it's not, just how these things works. I am using a small but powerful-for-its-size cordless drill.One hint is that sometimes you get more surface friction by going slower. Some people say do the whole thing slow, and sometimes slow is definitely quicker (sounds odd but is true) and sometimes it isn't. When it's not, I have the best luck varying the speed. Coated parts of ceramic (the interior and exterior surfaces) appreciate speed, once you get in to the clay material, slower grinders through it pretty effortlessly.In sum, there are "better" ones out there, but you will have to replace these with regular use in either case, so two for this price is actually better than buying a $30-60 bit that you last a little bit longer.Also, use water. A small spray or squirt bottle (or damp paper towel or sponge that you squeeze, will extend the life substantially. The combo of heat and friction (using without water) wears it down especially fast and makes the drilling slower and less precise in my experience.Please click helpful if you found this review informative or useful. Thank you!
