A rotary cutting implement includes a hammer cutting element. The hammer cutting element includes a shank. The hammer cutting element also includes a cutting head coupled to the shank having a first surface and a second surface. The cutting head includes a projection spaced apart from a blade defined on the first surface. The projection extends beyond a periphery of the shank by a first distance and the projection extends along an axis substantially oblique to a longitudinal axis defined by the hammer cutting element. The hammer cutting element also includes a coating disposed on a portion of at least one of the blade, the first surface and the second surface, and the hammer cutting element has a center of gravity that is offset from the longitudinal axis.

A rotary cutting implement includes a hammer cutting element. The hammer cutting element includes a shank. The hammer cutting element also includes a cutting head coupled to the shank having a first surface and a second surface. The cutting head includes a projection spaced apart from a blade defined on the first surface. The projection extends beyond a periphery of the shank by a first distance and the projection extends along an axis substantially oblique to a longitudinal axis defined by the hammer cutting element. The hammer cutting element also includes a coating disposed on a portion of at least one of the blade, the first surface and the second surface, and the hammer cutting element has a center of gravity that is offset from the longitudinal axis.

A lawnmower uses thin, replaceable blades with a hardened cutting edge and a cross-section defining an airfoil retained in cartridges that are inserted and removed from rotors in a blade assembly at need. The cartridges comprise a blade and rotor interlocking elements affixed to the blade, each rotor interlocking element corresponding to one rotor in the blade assembly. Each rotor and rotor interlocking element includes features that allow the two to be securely engaged so that the rotors may be spun quickly in a mower blade assembly to cut grass.

A lawnmower uses thin, replaceable blades with a hardened cutting edge and a cross-section defining an airfoil retained in cartridges that are inserted and removed from rotors in a blade assembly at need. The cartridges comprise a blade and rotor interlocking elements affixed to the blade, each rotor interlocking element corresponding to one rotor in the blade assembly. Each rotor and rotor interlocking element includes features that allow the two to be securely engaged so that the rotors may be spun quickly in a mower blade assembly to cut grass.

A cutting disc for a machine for harvesting stem-like plants includes a number of elements which together can be attached or are attached to a bracket forming a circular ring with an outer cutting edge. At least one of the elements is attachable to the bracket in a first position, in which a first edge of the element forms the outer cutting edge, and in a second position, in which a second edge of the element forms the outer cutting edge. No matter whether the element is in the first of second position, a circular cutting edge is made up.

A cutting disc for a machine for harvesting stem-like plants includes a number of elements which together can be attached or are attached to a bracket forming a circular ring with an outer cutting edge. At least one of the elements is attachable to the bracket in a first position, in which a first edge of the element forms the outer cutting edge, and in a second position, in which a second edge of the element forms the outer cutting edge. No matter whether the element is in the first of second position, a circular cutting edge is made up.

A lawnmower with a plurality of blade holding elements in a horizontally rotating blade assembly holds a plurality of blades in a blade channel. The blade assembly is covered by a blade assembly guard that is only open underneath at a point where blades in the blade assembly would cut grass during normal operation. A blade assembly access panel in the upper portion of the blade assembly guard allows blades or a blade assembly to be easily replaced.

A lawnmower with a plurality of blade holding elements in a horizontally rotating blade assembly holds a plurality of blades in a blade channel. The blade assembly is covered by a blade assembly guard that is only open underneath at a point where blades in the blade assembly would cut grass during normal operation. A blade assembly access panel in the upper portion of the blade assembly guard allows blades or a blade assembly to be easily replaced.

A lawnmower with a plurality of blade holding elements in a horizontally rotating blade assembly holds a plurality of multi-ductility blades with a maximum thickness of 0.075 inches in a blade channel and in a substantially tangential orientation. The multi-ductility blades include a hardened cutting edge of Rockwell hardness greater than 50 and ductile portion with Rockwell hardness less than 50.

A lawnmower with a plurality of blade holding elements in a horizontally rotating blade assembly holds a plurality of multi-ductility blades with a maximum thickness of 0.075 inches in a blade channel and in a substantially tangential orientation. The multi-ductility blades include a hardened cutting edge of Rockwell hardness greater than 50 and ductile portion with Rockwell hardness less than 50.