As per customer requirements 2 fluted through Coolant Drills upto L/D 25 times, Multistep Drills, Center Drills, Burnishing Drills. Drills & StepDrills-One to Three (Multiple) Steps. Through Coolant Hole Drill Left Hand Helix Drill. Center Drills Single End / Double End. Extra long drills L/D upto 25 times Burnishing Drills with hole tolerance IT8