1-1/2 NPT Thread Specs
Standard: ASME B1.20.1 (NPT)
Technical parameters and design data for the 1-1/2 NPT pipe thread.
Established under standard ASME B1.20.1, this thread uses a pitch of 0.08696 inches and has 11.5 threads per inch.
Often used in fluid, hydraulic, or pneumatic systems, NPT/BSP threads require suitable thread sealants to assure leak-tight performance.
Dimensional Specifications
Size Designation
1-1/2 NPT
Nominal Diameter
1.9 in(48.26 mm)
Major Diameter
2.2426 in(56.96 mm)
TPI (Threads per Inch)
11.5
Pitch
0.08696 in
Pitch Diameter
2.1861 in(55.53 mm)
Minor Diameter
2.1485 in(54.57 mm)
Tap Drill size
1-3/4 in
Quick Unit Converter
mm
⇄
inch
Frequently Asked Questions
What is the tap drill size for 1-1/2 NPT pipe thread?
The recommended tap drill size for a 1-1/2 NPT pipe thread is 1-3/4 inches.
What is the major diameter of a 1-1/2 NPT pipe thread?
For a standard 1-1/2 NPT pipe thread, the major diameter at the pipe reference plane is 2.2426 inches (approx. 56.96 mm).