鉄筋でドリル作る可能なのか?
<iframe width="1280" height="720" src="https://www.youtube.com/embed/At1U8wHO_co" title="A drill tool made of steel iron shaft drill developed by own skill | Thread tap making skills lathe" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>