I do about 10 of these surgeries a month. I typically get over 5000,000 feet of passage with each chisel on aromatic cedar (a very soft wood). They are exceptionally good, outperforming all other end grain bits. Usually the camp goes first. Only one in a hundred will blunt before the camp dies. I have to watch the wood burn where the bearing touches so I know when to change it. I can put too much pressure on my penboards, but I need it to get the results I want.