The Milwaukee 4-1/2 in. Hole dozer bi-metal hole saw with arbor has a new 3.5 TPI tooth design that offers you the longest life in metal applications. These Milwaukee Hole dozer bi-metal hole saws blades feature the industry's only lifetime tooth break warranty and can take on all general purpose applications, making them the most durable hole saws. All-access slots solve the frustration of plug removal, making you more productive with less downtime between holes. The new slot design also gives you increased pilot visibility for accurate placement and faster chip ejection keeping your cut cool. Hole dozer thermoset coating allows for faster cutting and is optimized for cordless tools, delivering you 25% more holes per charge.