Starrett's BI-Metal DEEP Cut Hole Saws are the perfect solution for cutting holes in wood, metal, and steel. The bi-metal construction provides extra strength and durability. The High-Speed Steel teeth are heat resistant, hard, and shatter-resistant with an alloy backing to prevent tooth breakage during extended use. Starrett's NVP progressive pitch technology provides the fastest cutting rates on the market today, maximizing your productivity by allowing you to cut more holes per minute than any other hole saw on the market. It comes with a 2" (51 mm) depth which improves cutting performance on tubes, particularly where there is a need to cut through both sides of the tube. It is excellent at cutting metal and non-ferrous metals. The L.S. Starrett Company, founded in 1880, manufactures more than 5,000 variations of Precision Tools, Gages, Measuring Instruments, and Saw Blades for industrial, professional, and consumer markets worldwide. Starrett has set the standard for fine precision tools in the industry for over 140 years. "Like all businesses, however large or complex, this one started with a man and an idea. The man was Laroy S. Starrett; his idea was 'to invent something useful that people would want.' Countless others have had a similar idea, the difference here was in the quality of the man. L.S. Starrett’s outstanding characteristic was confidence in himself; he was a man who in spite of one setback after another refused to admit defeat. He had the unusual ability, vision, and enterprise, but without his high courage this story of the foundation and growth could never have been written..."