Review on Disston 4435 Xtreme Coated Glass Tip by Joe Duncan

Don't worry about this bit, it doesn't start well, it only really chews when it's 1/4 cut. I drilled rocks and only got 5 holes before he stopped cutting. I usually use the Bosch GT700 and will only use it from now on. With only 2 blades they don't hold heat like this one. If you're drilling into tile and need a very clean hole, this may work for you but isn't strong enough for the rocks. Definitely not worth the price to me. :-(