A cutter disc for a tunnel boring machine includes a middle disc portion defining a radially outer surface or edge for engaging a surface, a left toothed portion defining a first set of teeth set back from the outer edge, and a right toothed portion defining a second set of teeth set back from the outer edge. In an embodiment, a central bore through the cutter disc is configured to attach the cutter disc to a hub for rotatably mounting the cutter disc on a shaft. In an embodiment, the hub is formed integrally with the cutter disc. The left and right toothed portions provide structural support to the middle portion and facilitate rotation of the cutter disc when boring in soft or mixed conditions, but do not interfere with boring in hard rock conditions.