ltra Fast Cutting Mini Holesaw Set with 8% Cobalt designed for drilling through sheet metal. These holesaws have a Ultra thin kerf HSS cutting edge with 8% cobalt for extra durability. Small, sharp and durable tooth design provides fast drilling in materials up to 1.6mm thick. The internal spring allows for continuous drilling without clogging. These holesaws can be used in Impact Drivers, and are suitable for cutting Stainless Steel, Steel and Aluminium.