I want to use a router to make 1/4″ finger joints for a small box. What would be the most appropriate bit to use straight, spiral upcut, or spiral downcut?
Michael Dresdner: All will work if you use a backer board, but I suspect a spiral downcut will give you the least amount of breakout.
Rob Johnstone: I think a simple straight bit is sufficient for a finger joint application. The other bits are more expensive and would not, in my opinion, provide much added benefit.