This ER40 collet set is designed to fit perfectly into an ER40 collet chuck, making it a versatile tool suitable for milling, drilling, and turning. Made of high-quality spring steel, it is highly durable and corrosion-resistant, ensuring a long lifespan. Each collet in the set is precision ground and hardened to ensure high accuracy and stability, making it suitable for high-precision machining tasks. The set includes a wide range of collet sizes, from 1/8"-1", allowing you to choose the right size for your needs. The collets come in a sturdy case for easy organization and storage, making them convenient to use and store. Whether you are a professional machinist or a DIY enthusiast, this ER40 collet set is an essential tool for your workshop.