Here are three tools for making the middle joint of a shakuhachi flute. The disc component sits on a long, rotating base, allowing it to spin smoothly. The conical part of the long base can shape rings, with a diameter ranging from 2.8 cm to 3.9 cm. The disc has a diameter of about 15 cm. The other component is for flattening silver rings. It's placed on top of the ring, and the ring's thickness is made uniform by hammering it from above. I bought these a long time ago (and they were quite expensive), but I've forgotten how to use them, so I can't offer support. I remember welding silver wire into a circle on the disc, then sandwiching it with the parts shown in the photo and hammering it to fine-tune the thickness and diameter.