Inner hole burnishing tools are divided into through hole burnishing tools and blind hole burnishing tools. Generally, blind hole burnishing tools can be used on through holes, but through hole burnishing tools can only be used on through holes. Because the through hole roller is used for the through hole burnishing tool (there is no holding groove in the middle), part of the shell and mandrel of the front section of the burnishing tool are exposed. If the blind hole is processed, the low end of the blind hole cannot be processed.

Of course, because the minimum R value of the front section of the needle roller of the burnishing tool is 0.5mm, even if the blind hole burnishing

tool is processing the blind hole, it cannot completely clean the root. It is recommended that the undercut be added at the bottom of the blind hole.