As a finishing of the gear, the gear honing is often used recently. Processing cost is sharply reducible if honing processing for work gear with different number of teeth can be carried out using one dressing gear. Moreover, when the work-gear's number of teeth and module is small, the grinding wheel generated by the dressing gear with different work-gear's number of teeth processes the work gear. In this paper, the geometric relation of three tooth surfaces (dressing gear, grinding gear, and work gear) was clarified. Consequently, it was shown that the grinding gear generated by the dressing gear with different work-gear's number of teeth and work gear constitute point contact gear pair. And, the tooth profile and lead error produced on the work gear tooth surface was calculated by numerical calculation.
