High Quality: The Genmitsu end mills are made of ultra-fine 0.2?m tungsten carbide steel alloy that can keep continuous machining 800 minutes. Moreover, its Nano Blue Coating /Titanium Coating with high hardness and heat resistance enables the tool's cutting edge to retain crucial sharpness and lubricity. This provides longevity and produces cutting results of the highest quality. 2-Flute Spiral Flat Nose Ball Nose End Mills -- Shank Diameter: 3.175mm, Cutting Diameter: 3.175mm, Cutting Length: 17mm, Overall Length: 38mm. Two End Mill Sets -- Shank Diameter: 3.175mm, Cutting Diameter: 0.8 - 3.0mm (0.8/1.0/1.2/1.4/1.6/1.8/2.0/2.2/2.5/3.0mm), Cutting Length: 17mm, Overall Length: 38mm, with Nano blue and Titanium coating. Applicable Materials: Widely used in various materials including plastics, aluminum, circuit board, wood, as well as other precision parts processing. Wide Compatibility: The MC40A end mills are compatible with most desktop CNC machines, such as the Genmitsu 3018 Series, as well as other industrial CNC machines. Just make sure you select the correct-sized collet for your device