Three-Piece Hand Tap Set, Tap Thread Size 1/4 In. -28, High Speed Steel, Bright (Uncoated), Thread Standard UNF, Thread Length 1 in, Overall Length 2 1/2 in, 75 Percent Thread Drill Size 5.45 mm, Thread Limit H3, Class of Fit 3B, Thread Direction Right Hand, Number of Flutes 4