Screw Thread Insert STI Tap, Thread Size 1/2 In. -20, UNC, Overall Length 3 37/64 in, High Speed Steel, Bright (Uncoated), Right Hand, Thread Length 1.65625 in, Tap Chamfer Plug, Thread Limit H3, Class of Fit 3B, Number of Flutes 4. This item has been restricted from sale in the following state (s): []