This Millgrain tool is for use on your lathe or Millgrain Machine to create professional decorative borders around the edges of rings or bracelets. Wheel is 1/4” (6mm) in diameter, mounted on 1/8" square x 2-1/2"L steel shank. Wheel is hardened and tempered to provide clean, well-defined imprints. Male style and Width of 1.0 mm. Made in USA.