Round burr for drilling or carving. We brought these in expressly for the lampworks for a class which involves adding layers of enamel, coldworking the bead to reveal layers by carving, and then reheating the bead to firepolish it. Diamond particles electroplated onto stainless steel. Also excellent for stone carving, cleanup work, glass, ceramics and metals. Always use water or a diamond lubricant when using diamond instruments of any kind to keep the diamonds cool to make the burr last longer, and to keep down any dust and particles. Shaft: 3/32 inch stainless steel. Total length: 1-3/4 inches (44.5mm). Grit: Medium/Fine (120-140). Head size (Dia x L): 4 x 4mm. Use with any rotary tool or flexshaft with an appropriately sized chuck.

4mm By the each.