I had to drill a hole in the concrete masonry to fit a round outdoor electrical box. After pre-drilling this material for the dryer vent, I wasn't looking forward to the job. The bit went through 2 1/2 inches of material in about 10 minutes, compared to four hours when using a different bit for the dryer vent. The hole was clean and the dust thrown up during drilling was minimal (but wear a mask anyway). There's nothing like having the right tool for the job.