Home Pipe Threads 1-1/4" NPT

1-1/4" NPT Thread Specifications

Complete dimensions for 1-1/4" NPT pipe thread. TPI: 11.5, Pitch: 0.08696" (2.209 mm).

Thread Dimensions

Designation1-1/4" NPT
Nominal Pipe Size1-1/4"
TPI11.5
Pitch0.08696" (2.209 mm)
Outside Diameter1.66" (42.16 mm)
Pitch Diameter1.6035" (40.73 mm)
Minor Diameter1.5533" (39.45 mm)
Taper Angle1.7899° (1:16 taper ratio)
Thread Depth0.06025" (1.53 mm)

Tap Drill Size

Tap drill: 1.5533" (39.45 mm)

Common Applications