A rectangular counter knife (1) with a larger diameter hole (1-B), the counter knife has (1) two lateral, longitudinal, parallel, rectangular and vertical walls (1-C) inferiorly forming a rectangular recess (1-D), the two rectangular, inferior and transversal guides (2-B) of the rotating disk (2), sup¬port the rectangular knife (1), adjusting a hex-nut (4) in a larger diameter hole (2-C), coincident to the hole (1-B), receiving these holes on inferior-superior di¬rection (1-B.2-C), a hex-head screw (5) initially by¬pass one of the two holes (6-A) centralized along one rectangular knife (6)with two side cutting edges (6-B)and their ends have (6-C), a constructive variant comprising a rectangular knife (7) with a longitudi¬nal, central and oblong opening (7-A), with two cen¬tral, opposite and semi-circular projections (7-A1) forming a circular central opening in the middle of the knife the rectangular knife (7) has two side cut¬ting edges (7-B) and two cutting edges on the ends (7-C).
