Abstract: A wheel dresser for precision grinding wheels made up of a housing supporting a rotatable diamond tool with a flat end and a housing supporting the two at an angle to the side edge of the wheel to be dressed. Base of the wheel dresser is magnetic and can be supported on a magnetic table. The dresser is adapted to be supported on a machine where the grinding wheel and table are adjustable up and down relative to one another. The tool is rotatable about its longitudinal axis so that it may cool and only a part of the cutting edge be engaged with the grinding wheel at any one time. The wheel can be dressed by moving the tool radially of the wheel.