This is a new Interstate 2-1/2-8 NPT High-Speed Steel (HSS G ground thread) pipe tap, part number 4662144, designed to cut tapered National Pipe Taper (NPT) internal threads per ANSI/ASME B1.20.1 in 2-1/2 inch nominal pipe size at 8 threads per inch. The tap features a hex shank for positive drive engagement with a tap wrench or machine holder, and the tapered cutting geometry produces the self-sealing 1-in-47 taper characteristic of NPT threads essential for pressure-tight pipe joints in plumbing, hydraulic, and pneumatic applications. Ground-thread (G) construction provides tighter thread tolerance and superior surface finish compared to cut-thread taps, making this tap suitable for use in steel, cast iron, aluminum, and similar machinable materials. The tap arrives in its original Interstate plastic case and is unused and uncoated (bright finish), consistent with standard HSS pipe tap construction for this size class.

Product Specifications
MPN4662144
BrandInterstate
Thread Size2-1/2 in
Threads Per Inch (TPI)8
Thread StandardNPT (National Pipe Taper)
Taper1 in/ft (1-in-47 included taper per ANSI/ASME B1.20.1)
MaterialHigh-Speed Steel (HSS)
Thread FormGround Thread (G)
Coating / FinishUncoated (bright)
Shank StyleHex shank
Country of OriginChina
Applicable StandardANSI/ASME B1.20.1