Review on 🔩 Effortless Drilling with Shuangjia Diamond Glass Drill Ceramic by Bob Fasho

These are good quality drill bits. I've used them on ceramic tiles and they went through easily. They don't have a center guide, however, so you'll need to start at a slight angle and "swing" into the cut so you end up with a hole that's not entirely level - there's a slight edge where to start. . No problem if the hole is eventually closed. It should get better with practice, but they are quite difficult to use at first. The larger one appeared to be self-lubricating, which is good because it doesn't overheat and thereby shorten its lifespan. Otherwise, be sure to spray it with some water when using drill bits to ensure they last a long time.