The viscosity of flowable abrasive mixture is an important parameter in abrasive flow machining(AFM).In order to give a quantificational definition about the viscosity of flowable abrasive mixture

the fuzziness of general definition of flowable abrasive mixture viscosity was analyzed

and viscosity levels of flowable abrasive mixture were classed by means of fuzzy mathematics theory.Membership functions of every class viscosity were established

and all parameters in the functions were determined by experiments of free flowing and extending.The membership degree of an unknown viscosity of flowable abrasive mixture can be calculated easily.The research results provide a useful means for choosing viscosity in practice

selecting other processing parameters in AFM

and forecasting the effects of AFM.