These bits will hold a maximum of 2 to 6 linear feet. Then they're dead as a doornail and start burning your firewood. The quarter inch bit lasted 18 inches and then failed completely. The rounded drill lasted six linear feet, after which the wood began to burn. Unless your project is a very, very soft wood like balsa, then look elsewhere. Think about it, if you're paying for a bit that isn't 18 inches long before you need to replace it, that's a consumable.