Features & benefits: cap-saw Cobalt Bi-Metal reciprocating saw blades are designed for contractor grade applications each blade consists of Cobalt alloy high speed steel teeth electron beam Welded to a lower alloy backbone provide a flexible, high performance blade for thin sheet or tube ferrous and non-ferrous metal and conduit cap-saw blades have c66-67 Rockwell hardened teeth which operates up to 10 times faster than carbon alloy blades