Tinksky 10pcs 140mm Anti Slip Handle Diamond Rifflers Needles Flat Files Product Name : Diamond Needle File. Color : Yellow, Siver Tone. Material : Metal, Plastic. Shank Dia. : 3mm. Total Length : 140mm. Safety and easy to use with the red plastic coated handle. For filing of curves and corners in hardened steel dies, glass, ceramic, rock, carbide, gold, platinum and other hard materials.