Abstract: A road grader of the type including a tiltable and vertically adjustable frame is utilized to dependingly support a heavy duty multibladed horizontal rotary cutter head. The frame supports a prime mover drivingly connected to the rotary cutter head and the latter includes a horizontal disc from which elongated blades are supported. The elongated blades include base and free ends and the base ends of the blades are pivotally attached to spaced peripheral portions of the disc for oscillation relative thereto about upstanding axes. The rotary cutter head is disposed between the front steerable and rear driving wheels of the road grader and the blade frame of the grader is provided with a rearwardly opening semi-truncated cone-shaped shield within whose lower periphery the forward outer marginal portion of the disc is received and beneath whose lower periphery the free ends of the blades carried by the forward half of the rotary disc project.