bi-metal unique® saw technology, a patented Starrett process, joins two strips of high speed steel to a backing steel utilizing solid-state diffusion bonding (rather than traditional weld or laser bonding) for 170% more weld contact area, to reduce fracture and breakage. After initial use, the teeth develop a groove in the thin center of backing material. As a result, the cutting stroke produces dual chips that are more easily removed from the cut. In controlled tests, bi-metal unique® cut 20% faster and lasted 22% longer than five competing premium blades. Dual Cut jig saw blades are the latest saw innovation from Starrett. They are the first jig saw blade with teeth that cut in both directions, virtually eliminating burrs from both sides of the cut. Dual Cut jig saw blades are manufactured using bi-metal unique® saw technology and have a Unified Shank® for use with both Universal and Bosch style machines.