I bought two of these at a local hardware store to complete a project I was working on and was attaching plywood to an old concrete slab around the house. However, I was very disappointed that I went through these two BOSCH 3/16" bits after ONLY drilling 20 2" holes or so. I really haven't drilled more than 1-2 holes in a row without giving the punch and pausing. I had only a few holes left to drill when the second drill started to fail, so I used one of my 5/32" drill bits to drill pilot holes which then allowed the 3/16" BOSCH bits to finally get the job done. In short, they worked well while they worked, but they didn't work very long. Obviously I need to invest in stronger bits of better quality so I'll start checking them out online tomorrow!