Features: 100% brand new and high quality Select high-speed steel, high hardness, high resistance Ultra-large shake design, facilitating high-speed operation acceleration chips Double head design, cost savings Wear resistant heat resistance, long service life Suitable for copper / stainless steel / aluminum alloy / cast iron / mold steel / steel Precautions:Users must use the type diamond diameter size of the machined part, reasonably select the center drill modelBefore using the tool, the rust-resistant oil must be washed to avoid cutting on the blade.The surface of the machined workpiece should be straight to avoid damage to the toolThere is an abnormality in the process of processing, it should be stopped immediately, and it can be processed after it is clear. Package Includes: 1xCenter Drill Bit Specifications: Material:High-speed Steel Size: As shown note: 1.Please allow 1-2mm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.