SPECIFICATION: Carbide Ball Nose end Mill With 1/4" shank, 2" overall length, can be used in routers with 1/4" collect. High Quality:made from solid tungsten carbide (TC),have a Titanium Nitride (TiN) surface to improve heat resistance and reduce wear. Used it strictly for steel, it worked great for that, eats metal fast, beautiful surface finish!Watch your stick out and travel speeds. Applicable Materials: cnc bits usually used for steel（Carbon steel/Alloy steel/Hardened steel/Cast lron, etc.） Wide Compatibility: sisona end mill bits are compatible with most desktop CNC machines, as well as other industrial CNC machines. Just make sure you select the correct-sized collet for your device. 4 Flutes Carbide Ball Nose end Mill Bits