Abstract: A blade for a rotary mower comprising an elongated, flat metallic member having first and second ends and a central aperture for mounting the member on a shaft for rotation in a cutting plane, each of the first and second ends having a leading cutting edge and a trailing cutting edge, the leading cutting edge being formed on a downturned portion of a leading edge of the metal member when the member is rotating in the cutting plane and the trailing cutting edge being formed on an upturned portion of an edge opposite the leading edge, the downturned portion being angled between 15 and 45 degrees with respect to the cutting plane. The blade may include air dams formed on upper and lower surfaces, respectively, of the member parallel to and coterminous with the cutting edges.