Check the listing for details. INTERSTATE 1-11/2 NPT HSS 7 FLUTE Pipe Tap. Condition: New. Listed at 101.59 USD. The Interstate 1-1/2 NPT HSS 7 Flute Pipe Tap is a high-quality, durable tool used for tapping pipes with a 1-1/2 NPT thread size. This pipe tap features 7 flutes for increased efficiency and precision when cutting into the pipe material. Its HSS construction ensures longevity and reliability in various metalworking applications. Ideal for professionals in the CNC, metalworking, and manufacturing industries, this pipe tap is a valuable addition to any workshop or tool collection.