Six Dozen #7 Ultra Reverse Tooth Flying Dutchman Scroll Saw Blades (Half Gross) Six Dozen #7 Ultra Reverse Blades (72 Blades) A top-grade, high-speed fretsaw blade with every third tooth reversed for cleaner sawing. The Ultra Blades have two teeth down and one up. Cuts straighter than most other blades. Splinter free finish with little or no sanding! blades are 5 inches long and Pinless.