20, 25, 51 mm included in the set Bi-metal material Hardened teeth made from high speed steel For both professionals and DIY enthusiasts Faithfull Quick Change Bi-Metal Holesaw Set Faithfull 3 Piece Quick Change Holesaw Kit, manufactured from bi-metal material with hardened teeth made from high speed steel with an 8% cobalt content for durability. Bi-metal holesaws offer increased safety as they will not shatter under load and the variable tooth pitch provides a fast and smooth cutting performance. The Faithfull Quick Change Holesaw Set is an essential tool for both professionals and DIY enthusiasts looking to achieve precision and efficiency in their drilling tasks. This versatile set includes bi-metal holesaws that provide enhanced durability and safety, making them ideal for various materials. One of the standout features of these holesaws is their resistance to shattering under load, ensuring a safer working environment. Whether you're tackling wood, metal, or other materials, the Faithfull Quick Change Holesaw Set minimizes the risk of accidents and enhances performance.