Cost-Effective: Coming with 4x 2-Flute tapered ball nose end mills, Shank Diameter: 3.175mm, Radius: 0.25, 0.5, 0.75, 1.0mm, Cutting Length: 15mm, Overall Length: 40mm. Versatile: Perfect for 3D machining jobs like molds, rapid prototyping, models and other other precision parts processing, these Tapered ball nose bits can do the best.