HRC65 end mills are usually made of cemented carbide and have the following characteristics: High hardness: Able to withstand high strength and high cutting forces, suitable for processing high-hardness materials. Good wear resistance: Reduce tool wear and extend service life. Sharp cutting: Able to achieve precise cutting and obtain good surface quality. Challenges of finishing high-hardness steel High-hardness steel has the following characteristics, which brings challenges to finishing: High hardness: Large cutting force, which is easy to cause tool wear and chipping. Good toughness: Chips are not easy to break and are easy to wrap around the tool. Poor thermal conductivity: The heat generated during cutting is not easy to dissipate, which is easy to cause tool overheating.