Have drilled a number of holes in bricks for sockets. The cutting performance is excellent. The screw that holds the center drill but always falls out after about 50% of the drilling depth. The screw is too short, of low quality and the retaining ring (snap ring) is no good. I have a long, high-strength screw, a high-quality retaining ring and a lock nut used. With this construction, the screw stopped and I could perfectly easily pierce the outlet holes. When the construction of the drill - as described - amends, then you have a great price / performance ratio.