This is professional quality made of Tungsten (TC) in the USA with a square head with 4 teeth 1/4 in diameter . This drill uses a special variable pitch flute design to improve chip evacuation and reduce wear. CNC routers are designed for metalworking. I found I could dive with my router with this, but it's actually designed for cutting metal on a commercial CNC machine. It's very sharp and well made. Shown in 2 pictures, this heavy duty TC bit has its own labeled protective tube. This gives me the opportunity to process steel and aluminum if I receive equipment for this. I recommend this Star Tool Inc. Brand Carbide Square End Mill - Submicron Grain Carbide End Mill for Steel/Hardened Metals - Variable Flute Spacing and Helix Design - 4 Flutes - 1/4" - Made in the USA by CA. I hope you've found the information and my review helpful.