The dual knives 442 may be used with many types of crops and materials such as corn cobs, soy bean and the like, and therefore, for example, the dual knives do not need to be changed between corn and soy beans.Each knife portion 450, 452 has a proximal end or mounting end with an aperture therethrough for mounting the dual knifes 442 to the rotor 444 such that the dual knives 442 may be pivotally