1、Aluminum Alloy: The hand twist drill is made of aluminum alloy, which is sturdy and durable, adopts a 0.3‑4mm adjustable chuck with a 3 jaw chuck. The tail can be rotated, which is sturdy and convenient for your operation. 2、Light Weight: The mini drill bit is light in weight, small in size, and does not take up space, suitable for processing wood, plastic, rubber, PVC, walnut, model, bone, horn, amber, olive, fiberglass and other materials. 3、High Speed Steel: PCB micro drill bits are made of high speed steel, suitable for processing PCB, ordinary FR‑4, CEM‑3 boards, SMT, CNC, molds, plastics, circuit boards, carbon fiber, composite boards, etc. 4、Easy to Carry and Store: This hand twist drill set is easy to carry and store in a toolbox or pocket, making your daily work more convenient. 5、Wide Application: This is a hand twisted drill set widely used for electronic assembly, tooling, model making, winding, home decoration, etc. 1 x Hand Twist Drill10 x Silver Twist Drill10 x Black and Yellow Twist Drill Bit 10 x PCB Micro Drill Bit 100 x Screw Eye Pins Item Type: Hand Drill Bit SetMaterial: Aluminum Alloy + High Speed SteelUses: Suitable for electronic assembly, tooling, model making, winding, home decoration, etc.Silver Twist Drill: Approx. 0.8mm / 0.03in, 0.9mm / 0.035in, 1.0mm / 0.04in, 1.1mm / 0.043in, 1.2mm / 0.05in (Each 2)Black and Yellow Twist Drill Bits: Approx. 0.8mm / 0.03in, 1.0mm / 0.04in, 1.2mm / 0.05in, 1.5mm / 0.06in, 1.8mm / 0.07in, 2.0mm / 0.078in, 2.2mm / 0.87in, 2.5mm / 0.10in, 2.8mm / 0.11in, 3.0mm / 0.12in (Each 1)PCB Micro Drill Specifications: Approx. 0.3mm / 0.01in, 0.4mm / 0.016in, 0.5mm / 0.02in, 0.6mm / 0.02in, 0.7mm / 0.027in, 0.8mm / 0.03in, 0.9mm / 0.035in, 1.0mm / 0.04in, 1.1mm / 0.043in, 1.2mm / 0.05in (Each 1)Adjustable Range of Hand Twist Drill Chuck: Approx. 0.3- 3.4mm /  0.01- 0.13in