Starrett fastcut general purpose reciprocating blades are excellent for all-around use. Made with the Starrett exclusive bi-metal unique process for exceptional durability and long life. 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 percent 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 percent faster and lasted 22 percent longer than five competing premium blades. Straight shape. 18 TPI. Measures 6-inches length by 3/4-inches width by 0.035-inches thickness.