Bi-Metal Reciprocating Saw Blades are suitable for thin sheet metals. The bi-metal blade is the combination of both a high carbon steel (HCS) body and a high speed steel (HSS) cutting edge. Giving strength and flexibility at both low and high temperatures. A tough shatter resistant blade that keeps its edge longer. Extended service life leads to greater cost effectiveness per blade. Milled & wavy set (MWS) teeth give a fine, straight cut.