Using these Industrial and Scientific cutting tools, our team found that they were excellent in quality and durability. The 4-inch shank power allowed us to work on deep surfaces with ease. The variety of pieces provided in the kit made it versatile and reliable for any task. The precision and accuracy of these drill bits impressed us greatly. The only downside is that the price falls on the high end, but the value of these bits is definitely worth it. Overall, we highly recommend these industrial drill bits for any construction or DIY project.