Three-Piece Hand Tap Set, Tap Thread Size 1/2 In.-20, High Speed Steel, Bright (Uncoated), Thread Standard UNF, Thread Length 1 21/32 in, Overall Length 3 3/8 in, 75 Percent Thread Drill Size 11.40 mm, Thread Limit H3, Class of Fit 3B, Thread Direction Right Hand, Number of Flutes 4