Pipe and Conduit Thread Tap, Thread Size 1/4 In. -18, NPT, Overall Length 2 7/16 in, High Speed Steel, Bright (Uncoated), Right Hand, Thread Length 1 1/16 in, 75 Percent Thread Drill Size 0.4375 in, Thread Limit Not Applicable, Class of Fit Not Applicable, Number of Flutes 5