High-quality materials This twist drill set is made of high-quality high-speed steel after hardening, heat treatment and polishing surface, high hardness, robustness and durability as well as a long service life. Suitable for wood and plastic 8 pieces/set The diameter of the tool holder is 1/2 inch; There are a total of 8 sizes with diameters of 14, 16, 18, 19, 21, 22, 24, 25mm; You can choose different sizes according to your drilling needs, and the tools are complete Widely Used Twist drill bits can be attached to hand and power drilling tools or used on drilling machines, milling machines, lathes and even machining centers; Suitable for carpenters, construction workers, electricians, workshops, DIY enthusiasts, craftsmen, hobbyists, etc. Portable We provide a wooden storage box for you to keep all the snail pieces together; This is convenient for your daily storage and transportation and is not easy to lose Quality Control We strive to provide high quality products and thoughtful service; If you have any questions during the purchasing process, please do not hesitate to contact us. We will respond to you within 24 hours