Freud DS0908BFD5 9-Inch x 8-10T Steel Demon Diablo Reciprocating Blade, 5-Pack N/A Imported Perma-shield coating protects the blade from heat, gumming, and corrosion 1 in. Demolition body delivers straighter cuts with less vibration Ultra-hardened cutting edge increases the hardness to a Rockwell hardness of HRC 62 versus HRC 55 for standard blades 9" Length 8-10 Teeth per Inch (TPI) Bi-Metal Liquid Metal Tooth Design Lasts up to 4x longer than standard blades For Cutting Steel & Metal Composites (1/8" to 1/2")