1/4-28 NF High Speed Steel Spiral Point Plug Tap. 2 Flutes. H3. • Spiral point taps are designed for machine tapping through holes in a wide variety of materials. The point of the tap continuously ejects the chips ahead of the tap, eliminating chip disposal problems and thread damage. - 1/4-28 NF High Speed Steel Spiral Point Plug Tap Norseman 1/4-28 NF High Speed Steel Spiral Point Plug Tap (60331)