Abstract: A rotary cutter includes a rotatable cutter blade and a grinding element supported on a support at one side relative to the cutter blade for grinding the cutter blade. A gap is normally kept between the grinding element and the cutter blade. The support is operable to move the grinding element into friction contact with the rotating cutter blade when grinding is necessary during a cutting operation of the rotary cutter. The grinding element can be normally kept in friction contact with the cutter blade so that a grinding effect is produced when rotating the cutter blade during a cutting operation.