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. These cutting blades are quite sharp and mainly used on copper, iron, aluminum, alloy and other medium hard thin metal material . They can also be used for non-metallic materials such as plastic, wood. Features: Made from high speed steel, with super wear resistance and long service life. Improved hardness. Under high speed it will show super fatigue fracture resistance of high speed steel. Strong cutting performance. A must have tool for carving working. Fine grinding repeatedly on blade surface, high standard of surface finish. Mainly used on copper, iron, aluminum, alloy and other medium hard thin metal material. Can also be used for plastic, wood, etc. Specifications: Materiel: HSS Inner Diameter: 6.35mm Outer Diameter: 22mm, 25mm, 32mm, 35mm, 44mm Thickness: 0.7mm(of 22mm, 25mm, 32mm) 0.8mm(of 35mm, 44mm) Maximum Speed: 20000rmp Extension Rod Diameter: Approx. 3.17 x 50 mm / 0.12 x 1.96" Weight: 40g(approx.) Package Includes: 1 Set x Cutting Blades(22mm&25mm&32mm&35mm&44mm) 2 x Extension Rods Note: 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. .