Durable: Made of high-quality high-speed steel, ensuring improved heat resistance of the hole teeth. The black paint surface provides good rust prevention and wear resistance, extending the service life of drilling engineering Usage: Suitable for aluminum, cork, plastic board, gypsum board, composite materials, etc. Clean cutting: Use fast cleaning cutting. Choosing different diameters can greatly improve work efficiency. Portable storage box: This set is equipped with a customized storage box for easy carrying, and the items have corresponding dedicated slots for easy access.