Router Bits

[Herb Smith]

Is there a difference in the cut cleanliness, including the bottom of the cut, between straight and spiral router bits? I know that there is a difference with removal of debris and price, but I'm not concerned with that.

[Lee Schierer]

I find that spiral bits give a cleaner bottom cut with less burning.

[Doug Dawson]

Is there a difference in the cut cleanliness, including the bottom of the cut, between straight and spiral router bits? I know that there is a difference with removal of debris and price, but I'm not concerned with that.

A spiral versus a straight bit is going to give you a cleaner surface because of the shearing action of the spiral bit, somewhat like a segmented jointer/planer head gives you a better surface than straight knives. Whether the degree of it is worth the extra cost is debatable, though, at least in the case of router bits.

[Dick Mahany]

Here's a very good video that discusses the merits of spiral router bits as well as upcut vs down cut as compared to straight bits. It's a little on the long side, but well done and may help shed some light. https://www.youtube.com/watch?v=mGaEiIewTQs