Lawn mower

A lawn mower comprising:

• a blade disk rotatable about a rotation shaft extending in an up-down direction;
• and
• a plurality of cutter blades mounted on the blade disk,
• wherein the blade disk integrally includes a disk base section of a flat disk shape mounted on the rotation shaft, an annular plate section surrounding the disk base section and having a plurality of depressed portions each depressed downward from an upper surface of the blade disk, a plurality of blade mounting sections each formed on a part of a bottom of a corresponding one of the depressed portions and having a corresponding one of the cutter blades mounted thereon, and a circumferential high-rigidity section for increasing rigidity of the blade disk between the blade mounting sections,
• the blade mounting sections are located near an outer circumferential edge of the blade disk and located on, and spaced from each other along, an imaginary reference circle concentric with a rotation center of the blade disk, and
• the circumferential high-rigidity section is located along the reference circle in such a manner as to interconnect the plurality of blade mounting sections along the reference circle, the circumferential high-rigidity section being formed in a generally concave-convex configuration by being depressed and protruded in a facewise direction of the blade disk.