Used for drilling wider holes in acrylic. I don't have a drill press so I use a drill press. They work fine. I attached the acrylic to the wood and drilled all the way down at low speed so as not to crack or melt the acrylic. They cut through acrylic and wood very well, even to full depth. Lowe had many more such sets. I haven't had much runtime, can't speak to durability, but if you need them for infrequent use they are great value.