| 摘要 |
<p>The present invention relates to a boring device comprising: a boring bar (100) inserted into a hole processing part of an insertion target object (200); and a guide main body (110) mounted on the boring bar (100) to change the size of the outer diameter. The purpose of the present invention is to improve the marketability and productivity of the boring device by properly processing a gap between the hole of the insertion target object (200) and the boring device and preventing burning and shake.</p> |
