Diablo's Flush Cut Bi-Metal Reciprocating Blades for Nail-Embedded Wood and Metal provide maximum and superior results. Perma-SHIELD coating protects these blades from heat, gumming, and corrosion. Patented aggressor Variable tooth technology incorporates a tooth count per inch (TPI) that drastically increases from the shank of the blade to the tip - allowing for super-fast cuts with less vibration.