Quality HSS M2 ensures sharp, fast in any material, offers good hardness, toughness, wear resistance Premium Heat treated HRC63-66 is durable and can withstand heavy duty operation for a long tool life Good Surface holds up lubricant better and lead coolant near the cutting edge for smoother drilling MT shank allows drills installed directly into the machine's spindle for high-torque applications The drills confirm to one of ANSI/ASME B94.11M, NAS907, and DIN345 standard;