MULTIPLE SIZE - This PCB drill bit set contains 10 different size: 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, each size has 5pcs; Varies sizes to meet different needs. HIGH QUALITY - Made of high quality tungsten steel, highly wear resistance, high hardness, bending strength, anti-impairment, with good milling and cutting performance, ensuring high efficiency. HIGH PRECISION - PCB Tip spiral flute reduces cutting force and improves hole accuracy.With , milling groove and clean , these sets of tool work quickly and cleanly, no glitches or scrap left. APPLICATION - Great for 3D Printer Nozzle Cleaning, Amber beeswax, circuit boards, bakelite, CNC engraving, jewelery, metal plastic and other precision drilling. ATTENTION - Shank diameter: . 1/8 (3.175mm) ; Total length: 1.5 inch(38.1mm); This drill is used on precision machines such as desktop engraving machines and high-speed rotary tables. Hand-held electric drills require high operating technology. Specification: diameter: 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9,1, 1.1, 1.2mm Effective blade length: 5.5mm~10mm Stem diameter : 1/8 inch (3.175mm) Drill point angle: 135 degree Length: 38.00 +/- 0.2mm Main uses: PCB circuit board, 3D printer, CNC Colour: colorful Material: tungsten carbide steel Size: 0.3-1.2mm Package Contents: 50 * PCB Drill Bits Set Note: 1. PCB drill bits which below 0.5mm are easy to break because they are small and thin. It is recommended to be careful when using them. 2. This tungsten steel drill bit is mainly suitable for high precision professional drilling equipment such as PCB drilling rigs. 3. When using, you must apply force evenly and vertically. Do not Press the blade with your hands or external force to avoid damage. 4.Due to the extremely high hardness of the drill bit, the toughness is low. Please don't fall to the ground, it is brittle and it may break. 5. Please note that this is not a quality issue, please purchase carefully if you mind it. Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.