Lenox 21064-610G is a 5-pack of 10TPI 6-Inch Titanium-Edge Reciprocating Blades. The Lenox 610G Gold Reciprocating Blades are designed for metal. The Lenox Gold blades are longer lasting because they have a reinforced tooth design and titanium coating which combine to dissipate heat and extend the life of the blade. They are also shatter resistant, the bi-metal blades bend and resist breaking to extend blade life and cut faster. The specially formulated titanium edge improves the wear resistance of the teeth for faster cuts throughout the blades life. Though the blades in the Lenox 21064 can be used for cutting wood and metal, they are particularly suited for metal applications.