A bulldozer is defined as a blade, normally mounted in front of a self-propelled machine, for scraping and pushing materials through forward motion of the machine. It is commonly an optional attachment to a crawler tractor and wheel tractor as defined in SAE J1057a. When the bulldozer is shown mounted on a tractor or other machine, the bulldozer specifications should be qualified by stating track shoe type or tire type, size, ply, and specified inflation pressure. Vertical measurements are referenced to the horizontal reference plane, which passes through the face of the track shoes. Items A—G are further defined by Fig. 1. Fig. 1 is not intended to be exactly descriptive of any particular machine. Ground is established with full grouser penetration.