Greenfield 282901 1/2-20 NF HS G H3 3FL PLG SPPT CNCHD TAP

These taps have a unified thread standard. UN coarse (UNC) taps have fewer threads per inch than UN fine (UNF) taps. Compared to UNF taps, UNC taps perform better in threading applications on brittle materials and are less likely to cross thread. Coarse threads can also withstand more physical abuse than fine threads. UNF taps have more threads per inch than 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.