EXTRA SLIM DIAMOND NEEDLE FILES These slim files allow easy access to difficult and complicated areas. Our Needle Files are perfect for grinding different metals and hard materials such as tungsten carbide, steels of 40Hrc and harder, ceramic materials, and glass. Total Length 140 mm -Diamond Coated Length 70 mm -3.0 mm Round Shank -Available in 120, 200 or 300 Grit x