It is a Hand Tools/Alloy Tools/Hand Drill/Hand Twisting Drill. Chuck Diameter: 0.4”. Material: Aluminium Alloy & High Speed Steel Twist Bits. Aliminium Alloy & High Speed Steel Bit. Application: Mainly used for Model, Resin, Jewelry, Walnut, Amber, Olive Nut, Buddha Beads, Ivory, Nut, Plastic, Wood, etc.