Spiral Point Tap, Thread Size 1/4 In.-28, UNF, Overall Length 2 1/2 in, High Speed Steel, Bright (Uncoated), Right Hand, Thread Length 5/8 in, 75 Percent Thread Drill Size 5.45 mm, Thread Limit H3, Class of Fit 2B, Number of Flutes 2 UN fine (UNF) taps have more threads per inch than UN coarse (UNC) taps. Compared to UNC taps, UNF taps perform better in threading applications on thin-walled workpieces and hard materials. Fine threads provide more tensile strength and shear strength than coarse threads. The bright finish on these taps provides a smooth, polished surface.
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