PURPOSE:To achieve accurate and stable positioning and to facilitate manufacture, by forming a section for line or face contacts with a tooth surface on a pitch line at a tooth rest section fittable with the tooth section of a bevel gear, and a contactless clearance which is continuous to said contacting section. CONSTITUTION:A contact section 23a which makes line contact or strip face contact with the tooth surface of a bevel gear and pitch line P of the bevel gear, and a clearance section 23b which is continuous to said contact section 23a and does not contact with the tooth surface of the bevel gear are formed at a tooth rest section 23 fittable with the tooth section of the bevel gear. Consequently. the tooth surface of the bevel gear is received by the contact section 23a of the tooth rest section 23 through line contact or face contact on the pitch line P, while other portions of the tooth rest section 23 serves as a clearance section 23b so as to avoid contact with the tooth surface of the bevel gear. As a result, the bevel gear is supported accurately and stably thereby machining accuracy is improved and manufacture can be facilitated when compared with a conventional jig.
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