Abstract: Provided is a grinding method capable of preventing variation in the outer diameter of a processed object 1 at the completion of grinding regardless of change in the amount of elastic deformation of the processed object 1 based on the change in the cutting ability of a grindstone 4. The outer diameter D of the processed object 1 during grinding is measured by gauge heads 5 in process. Plural target values Di that differ from each other are set for the outer diameter D of the processed object 1, and first threshold values are set for the rate of change of the outer diameter D of the processed object for each of these target values Di. Spark out is started when the outer diameter D of the processed object 1 becomes equal to a target value Di and the absolute value of the rate of change v is greater than a first threshold value that corresponds to the target value Di.

Abstract: Provided is a grinding method capable of preventing variation in the outer diameter of a processed object 1 at the completion of grinding regardless of change in the amount of elastic deformation of the processed object 1 based on the change in the cutting ability of a grindstone 4. The outer diameter D of the processed object 1 during grinding is measured by gauge heads 5 in process. Plural target values Di that differ from each other are set for the outer diameter D of the processed object 1, and first threshold values are set for the rate of change of the outer diameter D of the processed object for each of these target values Di. Spark out is started when the outer diameter D of the processed object 1 becomes equal to a target value Di and the absolute value of the rate of change v is greater than a first threshold value that corresponds to the target value Di.