Introduction The general concept and theory of Evo10id gearing is described by patents which are filed in most of the major industrial countries of the world. This technology describes the use of parallel axis pinions with small numbers of teeth meshing with specially designed helical gears to achieve relatively high ratios at high efficiencies with the complete absence of undercut in the Evo10id pinion. The calculations involved properly coordinate the tooth proportions of the pinion in conjunction with involute profile shifting and proper mesh face contact ratio for smooth@ continuous transfer of power from pinion to gear or gear to pinion. The design and manufacturing techniques of Evo10id pairs are tailored to provide maximum cost effectiveness in production.