Tap Adapter, Tap Size 13/16 In., Tap Square Size 0.489 in, Compatible with Product Type ANSI Taps, Coolant Fed Non-Coolant Through, Features Automatically Stops Spinning when Bottom is Reached, Prevents Broken Taps, Quick-Change Style, For Shank Type ANSI Tap Shank, For Use With ANSI and Metric/ANSI Shank Taps: 13/16 in, M20