Diablo's Diamond Grit Reciprocating Saw Blade for Cast Iron provides long blade life and maximum performance in cast iron, fiber cement, masonry and fiberglass. Thanks to a reinforced blade backing, these blades allow a straight and accurate cut in extreme materials and provide 6X the blade life of standard blades on the market. Diablo's Perma-SHIELD reduces material buildup and prevents gumming and corrosion. A thin kerf design also provides fast cuts for increased productivity.