An object of the present invention to increase the cutting performance of the mower and brush cutter, to provide a wear hardly rotating cutting blade to. An outer peripheral portion has a blade base 11, 13, 15, 17 which bears a plurality of back blades 12, 14 and rounded, which can be mounted on a mower or brush cutter approximately A rotary cutting blade 10 of circular shape, said a plurality of 70 degrees with respect to both the sharpening angle of the back edge horizontal in the range of 75 degrees, both sharpening angle of the plurality of blades bottom horizontal is in the range of 75 degrees from 65 degrees relative to, the surfaces are edged several blades bottom unlike the blade base adjacent to each other across one of the back edge, and is edged with a plurality of dorsal blades surface, be the same as the positive direction towards being edged is adjacent blades bottom face of the rotation of each rotary cutting blade, the blade base adjacent toward the opposite directions of rotation are respectively edged surface and I differ.BACKGROUND 1【課題】草刈機や刈払機の切断性能を高め、摩耗しにくい回転刈刃を提供する。【解決手段】外周部に複数の背刃12,14,16,18及び丸みを帯びた刃底11,13,15,17を有する、草刈機又は刈払機に装着することが可能な略円形の回転刈刃10であって、前記複数の背刃の研ぎ角度がいずれも水平面に対して70度から75度の範囲内であり、前記複数の刃底の研ぎ角度がいずれも水平面に対して65度から75度の範囲内であり、複数の刃底が研がれている面は一つの背刃を挟んで隣接する刃底において異なり、複数の背刃の研がれている面は、それぞれ回転刈刃の回転の正方向に向かって隣接する刃底が研がれている面と同一であって、それぞれ回転の逆方向に向かって隣接する刃底が研がれている面と異なる。【選択図】図1
