Description:These cutting blades are made from strong high speed steel for durability, high hardness, fast and precision cutting. They offer extra long service life and ensure straight, accurate cutting. When cutting stainless steel material, high speed steel with high nitrogen or coating blade milling cutter should be used. With high hardness and high temperature resistant nitride coating the surface, these cutting blades are quite sharp and mainly used for processing or cutting off on copper, iron, aluminum, alloy and other medium hard narrow and deep slot metal material . They can also be used for milling process on non-metallic materials such as plastic, wood.Specifications:Materiel: HSSInner Diameter: 6.35mmOuter Diameter: 22mm, 25mm, 32mm, 35mm, 44mmThickness:0.7mm(of 22mm, 25mm, 32mm)0.8mm(of 35mm, 44mm)Maximum Speed: 20000rmpExtension Rod Size: 3.17 x 50mm / 0.12 x 1.96"Weight: 31g(approx.)Package Includes:1 Set x Cutting Blades(22mm&25mm&32mm&35mm&44mm)1 x Extension RodNote:1. Please allow 1-2mm error due to manual measurement. Thanks for your understanding.2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.