Three-Piece Hand Tap Set, Tap Thread Size 7/8 In.-9, High Speed Steel, Bright (Uncoated), Thread Standard UNC, Thread Length 2 7/32 in, Overall Length 4 11/16 in, 75 Percent Thread Drill Size 19.50 mm, Thread Limit H4, Class of Fit 3B, Thread Direction Right Hand, Number of Flutes 4