Abstract: A method of testing the characteristics of a file by providing a curve of the amount of material removed from a test bar as a function of the effective stroke area over which the file has been moved, the slope at a specified value of material that has been removed representing the cutting efficiency of the file and the value of the effective stroke area at such specified value representing the useful life of the file. Further, curves of the minimum filing forces needed to move the file for a selected stroke distance at selected compressive forces and of the maximum compressive forces which will not prevent a filing operation at selected filing forces can be used to determine the sharpness of a file relative to other files that have been similarly tested.