Drill America 1/2"-20 Unf High Speed Steel Left 4 Flute Tap Set Drill America DWT Series High Speed Steel Left hand taps are the most versatile taps for hand use, or for tapping under power. Hand taps are popular for use in general machine tapping or CNC tapping. For re-threading and making new threads. High Speed Steel Hand Taps come in three styles: Taper Style: Starts the thread square with the workpiece. Plug Style: Generally used in thru holes. Bottom Style: Generate the thread to the bottom of the hole. A tap set contains 1 taper, 1 plug and 1 bottoming tap. Used to make new threads or re-thread damaged and/or jammed threads Left hand cut, also called a "reverse tap" High speed steel hand taps are the most versatile taps for hand use, or for tapping under power Hand taps are popular for use in general machine tapping or CNC tapping