I'm was looking at buying a plunge router for a project where I need to cut groves into wood for finger holds which will be up to 55mm deep and probably 20-25mm wide. Ideally I would like the bottom of the groove to have rounded edges so was specifically searching for round nose router bits however I couldn't find any that will cut to this depth or even width. I've seen some that can cut to 30mm depth. I haven't used a router before but I assume that you cannot cut with a router bit deeper than the length of the cutting edge, is that correct? Can anyone point me to some place where I might be able to get such router bit. If such is not available then I will settle for a non rounded end.