{"data":{"fields":"term_definition","term_definition":"<div class=\"definition\">Mismatch Contact Ratio, or Modified Contact Ratio, is equal to the square root of the sum of the squares of the Transverse Contact Ratio and the Face Contact Ratio. Based on a localized tooth bearing, which under full load will extend to the extremeties of the working tooth profile, this value gives the resultant contact ratio. For optimum smoothness and quietness this value should be greater than 2.0. It may now be recognized that since this contact ratio combines both Transverse contact Ratio and Face contact Ratio it is the best guide to a good gear design. In many cases of spiral bevel and hypoid gear designs when low tooth numbers are used for the pinion and stubbed proportions must be used for depths, the Transverse Contact Ratio cannot be made equal to unity, usually it has a value of approximately 0.9. miter gear n<\/div>"}}