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) 10" ...
Pipe Outside Diameter (D) 10.75 273.05
Pitch (TPI) (P) 8.000 203.2
Pitch (Distance) (P) 0.125 3.175
Thread Tapper Angle (ß) 1.7893° 1.7893°
Thread V half Angle (α) 30° 30°
Height of sharp V (H) 0.108253 2.75
Thread height (h) 0.1 2.54
Pitch Diameter at the Pipe's end (E0) 10.54531 267.851
Minor Diameter at the Pipe's end (K0) 10.4453 265.311
Hand-Tight Engagement Length (L1) 1.21 30.734
Pitch Diameter at L1 plane (E1) 10.62094 269.772
Length of Last Complete Thread (L5) 1.675 42.545
Pitch Diameter at L5 plane (E5) 10.65 270.51
Length of Last usefull Thread (L2) 1.925 48.895
Pitch Diameter at L2 plane (E2) 10.66562 270.907
Overall Thread Length (L4) 2.3587 59.911
Length of Vanish threads (V) 0.4338 11.019

10-8 NPT - External (pipe) Drawing

Overview Drawing

Profile Drawing

10-8 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) 10" ...
Pipe Outside Diameter (D) 10.75 273.05
Pitch (TPI) (P) 8.000 203.2
Pitch (Distance) (P) 0.125 3.175
Thread Tapper Angle (ß) 1.7893° 1.7893°
Thread V half Angle (α) 30° 30°
Height of sharp V (H) 0.108253 2.75
Thread height (h) 0.1 2.54
Pitch Diameter at the fitting's end (E1) 10.62094 269.772
Length of Hand-Tight Engagemen (L1) 1.21 30.734

Length of Wrenching Allowance (L3)

0.25 6.35
Pitch Diameter at L3 plane (E3) 10.52969 267.454
Tap Drill Size (T) N/A N/A

10-8 NPT - Internal (Fitting) Drawing

Overview Drawing

Profile Drawing

10-8 NPT - Tolerances

Property Minimum Maximum
Thread Height (h) 0.09275" (2.356 mm) 0.1" (2.54 mm)
L1 gage Tolerance (+/- 1 Turn) (L1) ... 0.125" (3.175 mm)
Thread Truncation (f) 0.0041" (0.104 mm) 0.0078" (0.198 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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