Step up to a 1⁄2" shank to rout cleaner recesses
Our first attempt at routing the marble recesses in a game board resulted in an unacceptable amount of tear-out, top photo. After switching from a roundnose bit with a 1⁄4 " shank to one with a 1⁄2 " shank, the tear-out went away, bottom photo. Why? Thicker shanks flex (and chatter) less during operation.
—from the WOOD® shop