A rotary planing tool comprising a disk having a central mount for mounting on an angle grinder. The rotary planing tool has a working radial surface in which substantially radially extending blades are attached. The working radial surface has radial voids extending before a leading edge of each blade. The blades extend proud of the working radial surface, and each have a curvature tending away from the working radial surface into the circumference of the disk, and are arranged to not extend past the outer circumference of the disk.