PROBLEM TO BE SOLVED: To provide a mowing rotary blade that can smoothly perform replacement work of the rotary blade to a mowing machine, and stabilize a contact position of the blade part to the ground, thereby preventing the chipping or the like of a cutting edge, and extending the life of the rotary blade, and can reduce a work load to a worker to thereby improve efficiency of work.SOLUTION: A mowing rotary blade includes a mounting flat part with a mounting hole to a mowing machine formed in a central position, and a blade part annularly formed on an outer circumference side of the mounting flat part and provided with a cutting edge on the outer circumferential edge. The blade part is formed in a curved surface shape protruding to a back side of a base metal from the outer circumferential edge of the mounting flat part to the cutting edge. The deepest depth dimension is set larger than the projecting dimension of a mounting bolt when the mowing machine is mounted on the surface side of the mounting flat part with the mounting bolt, and the cutting edge is positioned on the back side of the base metal apart from the mounting flat part for a predetermined dimension .COPYRIGHT: (C)2014,JPO&INPIT【課題】回転刃の刈払い機に対する交換作業をスムーズに行いつつ、刃部の地面に対する接触位置を安定化させて、刃先の欠け等を抑制し回転刃の寿命を延ばすことができると共に、作業者への作業負担を軽減させて作業能率を向上させることが可能な刈払い用回転刃を提供する。【解決手段】中心部分に刈払い機への取付孔が形成された取付平坦部と、該取付平坦部の外周側に円環状に形成されその外周縁に刃先が設けられた刃部と、を備え、刃部は、取付平坦部の外周縁から刃先にかけて台金の裏面側に膨出した曲面形状に形成され、その最深部の深さ寸法が、取付平坦部の表面側に刈払い機を取付ボルトで取付けた際に該取付ボルトの突出寸法より大きく設定されると共に、刃先が取付平坦部より所定寸法台金の裏面側に位置することを特徴とする。【選択図】図2
