Guhring STI Tap, Green Ring, Series: 3989, Measurement System: Imperial, #6-40 Thread, UNF Thread, 2.126 in Overall Length, 3 Flutes, Modified Bottoming Chamfer, Right Hand Cutting Direction, Class of Fit: 3B, 0.168 in Shank Diameter, 0.143 to 0.15 in Tap Drill, 0.152 in Square, HSS-E, TiN Coated