Widely used to Drill the Metal, Aluminum Alloy, Copper, Stainless steel and Wood Drilling is Processed by Quenching to Ensure Excellent Performance The Large Spiral Angle Design Increases the Cutting Chip Flute Black Oxide Finish Reduces WearWhile Promoting Chip and Coolant Flow on Ferrous Materials Cutting Diameter from 13mm to 50mm is Available, Step by 0.5mm