United Spiral Fluted, Tin Coated M-35 Grade

Spiral taps are one of the most commonly used taps in the U.S. These taps have flutes that encircle the axis of the tap in a helical (or spiral) manner. Spiral taps are especially important when tapping blind holes (holes that penetrate material partially, not completely). Spiral fluted taps have flutes that wrap around the tap's axis in a spiral or a helical con- figuration. The tap is used mainly for tapping threads in blind holes.