I bought these pilot drill bits for a project that required drilling a large number of pilot holes in soft maple material. Imagine my surprise when the pilot bit broke after I drilled nine holes in a pine fixture I needed for a project. These nine wells were drilled consecutively within 45 minutes. I thought that although the drill worked adequately, the sinker seemed tedious and difficult to operate. The most annoying thing about this purchase is that now you have to start a new search for a suitable tool.