Union Butterfield® Pipe Tap, Straight Flute, Series: 1541, Measurement System: Imperial, 1/2-14, NPT, Tapered Chamfer, 1-3/8 in Thread Length, 3-1/8 in Overall Length, 4 Flutes, Right Hand Cutting, 0.688 in Shank Dia, 0.515 in Square Size, HSS, Bright, Medium Hook