A power tool in one embodiment is a table saw which includes a swing arm assembly movable along a swing path, an actuator configured to force the swing arm assembly away from a first swing arm position and toward a second swing arm position, and a riving knife positioned outwardly of the swing arm assembly when the swing arm assembly is in the first swing arm position, the riving knife including a channel with a first end portion and a second end portion, a first curved channel portion with a first center of curvature and located between the first end portion and the second end portion, and a second curved channel portion with a second center of curvature and located between the first end portion and the second end portion, wherein the first center of curvature is not coincident with the second center of curvature.