4-40 White Ring Straight Flute Semi-Bottoming DIN 371 Standard Tap, HSS-E (Cobalt), H2/H3, Steam Oxide Finish Type: White Ring,Number of Flutes: 3,Hole Type :Blind Hole 56mm Overall Length, 3.5mm Shank Diameter, 18mm Threading Depth, Without Coolant Through, Chamfer Form C: 2 to 3 Lead Threads Series No. 1979, Order Code 02.8450, Guhring Part #9019790028450