[Sizes] 10 different sizes to meet your different needs, Cutting edge diameter: 0.8-3.175mm (0.8/1.0/1.2/1.5/1.6/1.8/2.0/2.4/3.0/3.175mm). Shank diameter: 3.175mm. Total length: 38mm [Material] Made of tungsten carbide and nano blue coated with good milling and cutting performance, high working efficiency [Advantage①] These engraving bits have sufficient bending strength and wear resistance. The well-polished surfaces are quite sharp, clean, and there is no interference or burr on the shaft. [Advantage②] Nano-coating technology greatly increases the service life of the product and is suitable for groove milling, hole boring and edge grinding [Application] PCB, SMT, CNC, mold, plastic fiber, carbon fiber, super hard wood, printed circuit board and other precision parts processing 10 Size 1/8' Shank CNC Rotary Burr Set with Nano Blue Coating for Die Grinder Electric Drill Size: Total length: 38mm, cutting diameter: 0.8-3mm(0.03-0.12in), shank diameter: 3mm(1/8inch) Made of tungsten