Sugar cane stalks are conveyed along a path passing between upper and lower chopper drums equipped with chopper blades extending lengthwise of the drums and located so that blades of one drum intermesh with those of the other so as to cut the cane stalks into billets. The cutting diameter of the blades of the upper chopper drum is greater than that of the blades carried by the lower blade resulting in the peripheral speed of the upper chopper drum being greater than that of the lower chopper drum. The cutting edge of each of the blades is defined at one side by a compound bevel with the blades being disposed on the drums so that they overlap and mesh bevel-to-bevel. The compound bevels are chosen so as to both satisfy the requirement that the blades be self-sharpening and have close to a zero timing angle.
