Abstract: The mower blade with replaceable inserts includes a blade bar having diametrically opposite reliefs therein for replaceable cutting inserts. Headed pins extend from each relief, and each insert has corresponding slots. The slots have larger diameter outer ends to clear the larger diameter heads of the pins, the inner portions of the slots being stepped to fit closely about the narrower shanks of the pins. The inserts drop into position over the corresponding pins, and slide outwardly to be retained by the heads of the pins. The outer (lower) surfaces of the heads of the pins are coplanar with the outer (lower) surfaces of the inserts when installed. The cutting edge portions of the inserts extend over and are in direct contact with the corresponding leading edge portions of the blade bar, thus protecting the bar and transferring impact forces directly to the bar rather than through the pins.

Abstract: A lawnmower blade assembly, including a replaceable cutting edge insert and method for its use. The cutting edge insert is disposed within a recess of a support member at each end of a centrally rotatable main blade. The recess has a blunted front edge, a back shoulder, an outside shoulder, and a passage for an insert release tab. Two threaded preset Allen bolts, protruding from the recess floor, are permanently locked into position. The bolts are not specifically designed to carry the load of the rotating lawnmower blade. The back and outside shoulders of the recess provide most of the force necessary to retain the insert against rotational and centrifugal forces. The cutting edge insert, having substantially the same profile as the recess, and having slotted holes for reception of the bolts, can be slid in and out of the recess. An interference-type friction fit exists between the preset bolt head and the floor of the recess.