Pipe Thread data sheet


External (pipe) Basic Thread Dimensions

For interpertations of the terms scroll down to the drawings below the table

Property Inch mm
Nominal Pipe Size (Ø) 1" ...
Pipe Outside Diameter (D) 1.315 33.401
Pitch (TPI) (P) 11.500 292.1
Pitch (Distance) (P) 0.08695652 2.209
Thread Tapper Angle (ß) 1.7893° 1.7893°
Thread V half Angle (α) 30° 30°
Height of sharp V (H) 0.075307 1.913
Thread height (h) 0.06957 1.767
Pitch Diameter at the Pipe's end (E0) 1.21363 30.826
Minor Diameter at the Pipe's end (K0) 1.1441 29.06
Hand-Tight Engagement Length (L1) 0.4 10.16
Pitch Diameter at L1 plane (E1) 1.23863 31.461
Length of Last Complete Thread (L5) 0.5089 12.926
Pitch Diameter at L5 plane (E5) 1.24543 31.634
Length of Last usefull Thread (L2) 0.6828 17.343
Pitch Diameter at L2 plane (E2) 1.2563 31.91
Overall Thread Length (L4) 0.9845 25.006
Length of Vanish threads (V) 0.3017 7.663

1-11.5 NPT - External (pipe) Drawing

Overview Drawing

Profile Drawing

1-11.5 NPT - Internal (Fitting) Basic Thread Dimensions

For interpertations of the terms scroll down to the drawings below the table

Property Inch mm
Nominal Pipe Size (Ø) 1" ...
Pipe Outside Diameter (D) 1.315 33.401
Pitch (TPI) (P) 11.500 292.1
Pitch (Distance) (P) 0.08695652 2.209
Thread Tapper Angle (ß) 1.7893° 1.7893°
Thread V half Angle (α) 30° 30°
Height of sharp V (H) 0.075307 1.913
Thread height (h) 0.06957 1.767
Pitch Diameter at the fitting's end (E1) 1.23863 31.461
Length of Hand-Tight Engagemen (L1) 0.4 10.16

Length of Wrenching Allowance (L3)

0.2609 6.627
Pitch Diameter at L3 plane (E3) 1.19733 30.412
Tap Drill Size (T) 1.1406 28.971

1-11.5 NPT - Internal (Fitting) Drawing

Overview Drawing

Profile Drawing

1-11.5 NPT - Tolerances

Property Minimum Maximum
Thread Height (h) 0.06261" (1.59 mm) 0.06957" (1.767 mm)
L1 gage Tolerance (+/- 1 Turn) (L1) ... 0.08696" (2.209 mm)
Thread Truncation (f) 0.0029" (0.074 mm) 0.0063" (0.16 mm)
Tapper angle Variation (ß) 1.641" ( ) 2.089" ( )
Thead V Half Angle (+/-) (α) ... 0.75" ( )
Thread Height (h) " (0 mm) " (0 mm)
L1 gage Tolerance (+/- 1 Turn) (L1) " ( ) " ( )
Thread Truncation (f) " (0 mm) " (0 mm)
Tapper angle Variation (ß) " ( ) " ( )
Thead V Half Angle (+/-) (α) " ( ) " ( )
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