Item Type: Step Drill Bit Material: HSS high speed steel + Ti coating Package List 1 x Automatic Centring Stamp 3 x Step Drill Bit 1 x Storage Bag(random color) 1Groove Design Prevent Flying Away: The groove design prevents the metal filler from flying away and removes chips faster, so you can drill more smoothly without heating 2Reduce Slippage: The angle of the furcation tip is 118 degrees to reduce slippage and increase wear resistance 3Easier and Safer to Install: Hex handle is easier and safer to install in all power tools, especially for snapping into quick change chucks. It is best to clamp the gun drill to prevent slipping and falling off during rotation 4For various Materials: Step drill can be used with many different materials, such as steel, brass, wood, plastic, copper, fiberglass and PVC 5Increase Durability: Made of high speed steel material and Ti coating to increase durability and bit life