Abstract: A blade assembly for equipment such as a bulldozer, snow plow or the like has a moldboard and a replaceable blade. A plurality of rearwardly projecting lugs are provided adjacent the top edge of the blade and a corresponding plurality of sockets are provided adjacent the lower edge of the moldboard. The upper and lower surfaces of the lugs are horizontal while the side surfaces diverge rearwardly. The moldboard sockets are correspondingly configured but of greater width than the lugs. A locking bar having forwardly projecting locking lugs is detachably mounted on the rear face of the moldboard. The locking lugs are of such configuration as to substantially completely fill the portion of the socket remaining open when the blade lug has been inserted and shifted laterally in the moldboard socket.