The bit is a step bit, so a normal sharpener for twist bits won't do it. They stay sharp a long time though and then can either be replaced or sharpened at the shop or by a professional. i happen to be building a bookcase for my granddaughter right now, and used my k3 tonight assembling trim to surround the bottom and elevate the bottom shelf. I will use it on other parts as well, although I still use other joinery such as biscuits, mortise and tenon, and dado's as well.