Tool wear to a certain limit will no longer continue to use

Tool wear to a certain limit will no longer continue to use, the wear limit is called blunt standards.  grinding wheel  Standard ISO uniform regulations after the surface was measured with the wear width VB as a blunt tool wear standard. In actual production, in order to be more convenient, quickly and accurately determine the tool wear, tool life generally is to indirectly reflect the standard blunt tool.
After sharpening the cutting tool from the beginning up until the amount of wear experienced by blunt  Abrasive grinding wheel  total cutting time is called the tool life. Tool life and tool regrinding tool life is the product of the number of times that a new tool into use until retirement from the start until the total cutting time.