Speed Tiger Carbide Spiral Router Bits Down Cut - Ised1/4? Diameter, 1? Cutting ? APPLICATION - Our carbide tools are highly effective for working with Wood, Aluminum, Copper, MDF, Carbon Steels (~HB225), Alloy Steels (HB225~325), Pre-hardened Steels (up to HRC45), Hardened Steels (HRC40~45), and Cast Iron. ? HIGH-PERFORMANCE MATERIAL - Crafted from micrograin carbide, this end mill offers exceptional toughness, durability, and machinability, delivering outstanding performance and great value for its price. ? MULTI-SIZE - No matter what project you are working on, you can find the right size mill bits in our products to work better. (1/4", 1/2", 3/8", and 1/8") ? FINE WORKMANSHIP - Our products deliver outstanding high accuracy with an error of -0.02mm, empowering users to achieve professional cutting quality effortlessly. ? DEDICATED SUPPORT - Feel free to reach out to us via Amazon for the Cutting Condition Data, ensuring you get the most suitable product for your needs.