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NPT, ANPT and NPTF thread data Table. Note that NPT 5" to 24" OD sizes are not included in the table.

NPT, ANPT and NPTF

NPTR
NPTG and NPTC
External Pipe NPT Thread Dimensional Data Table
Pipe
Size |
T.P.I |
D |
O.D. |
O.D.
of Valve |
NPT
ANPT
NPTR
NPTF |
NPTG |
NPTC |
1/16 |
27 |
.313 |
- |
- |
1/8 |
27 |
.405 |
- |
- |
1/4 |
18 |
.540 |
- |
- |
3/8 |
18 |
.675 |
- |
- |
1/2 |
14 |
.840 |
.863 |
- |
3/4 |
14 |
10.05 |
1.081 |
- |
3/4-14NPTC-1 |
- |
- |
1.096 |
3/4-14NPTC-2 |
- |
- |
1.114 |
3/4-14NPTC-3 |
- |
- |
1.134 |
3/4-14NPTC-4 |
- |
- |
.159 |
1 |
11-1/2 |
1.315 |
1.346 |
- |
1-1/2 |
11-1/2 |
1.660 |
- |
- |
1-1/2 |
11-1/2 |
1.900 |
- |
- |
2 |
11-1/2 |
2.375 |
- |
- |
2-1/2 |
8 |
2.875 |
- |
- |
3 |
8 |
3.500 |
- |
- |
* 3-1/2 |
8 |
4.000 |
- |
- |
* 4 |
8 |
4.500 |
- |
- |
* Does not include ANPT, NPTF, NPTG or NPTC.
Pipe
Size |
T.P.I |
Pitch Dia. Small End Pipe |
Eo |
Tolerance |
E6 |
Tolerance |
NPT
ANPT
NPTF
NPTG
NPTC |
Turns
of
Gage |
Inches
on
Dia. |
NPTR |
Turns
of
Gage |
Inches
on
Dia. |
1/16 |
27 |
.2712 |
One
Turn
Large
One
Turn
Small |
± .0023 |
- |
One
Turn
Large
One
Turn
Small |
|
1/8 |
27 |
.3635 |
± .0023 |
- |
|
1/4 |
18 |
.4774 |
± .0035 |
- |
|
3/8 |
18 |
.6120 |
± .0035 |
- |
|
1/2 |
14 |
.7584 |
± .0045 |
.7718 |
+ .0000
- .0045 |
3/4 |
14 |
.9677 |
± .0045 |
.9811 |
+ .0000
- .0045 |
3/4-14NPTC-1 |
.9677 |
± .0045 |
- |
+ .0000
- .0045 |
3/4-14NPTC-2 |
.9856 |
± .0045 |
- |
+ .0000
- .0045 |
3/4-14NPTC-3 |
1.0057 |
± .0045 |
- |
+ .0000
- .0045 |
3/4-14NPTC-4 |
1.0302 |
± .0045 |
- |
+ .0000
- .0045 |
1 |
11-1/2 |
1.2136 |
± .0054 |
1.2299 |
+ .0000
- .0054 |
1-1/2 |
11-1/2 |
1.5571 |
± .0054 |
1.5734 |
+ .0000
- .0054 |
1-1/2 |
11-1/2 |
1.7961 |
± .0054 |
1.8124 |
+ .0000
- .0054 |
2 |
11-1/2 |
2.2690 |
± .0054 |
2.2853 |
+ .0000
- .0054 |
2-1/2 |
8 |
2.7195 |
± .0078 |
2.7508 |
+ .0000
- .0078 |
3 |
8 |
3.3406 |
± .0078 |
3.3719 |
+ .0000
- .0078 |
* 3-1/2 |
8 |
3.8375 |
± .0078 |
3.8688 |
+ .0000
- .0078 |
* 4 |
8 |
4.3344 |
± .0078 |
4.3656 |
+ .0000
- .0078 |
* Does not include ANPT, NPTF, NPTG or NPTC.
Pipe
Size |
T.P.I |
Pitch Dia. Small End Pipe |
Eo |
Tolerance |
NPT
ANPT
NPTR
NPTF
|
NPTG
at
L1 + S
Thrd
|
MNPTC
at
L1 + 8-1/2
Thrd
|
1/16 |
27 |
.2875 |
- |
- |
1/8 |
27 |
.3800 |
- |
- |
1/4 |
18 |
.5025 |
- |
- |
3/8 |
18 |
.6375 |
- |
- |
1/2 |
14 |
.7918 |
.8008 |
- |
3/4 |
14 |
1.0018 |
1.0112 |
- |
3/4-14NPTC-1 |
- |
- |
1.0268 |
3/4-14NPTC-2 |
- |
- |
1.0447 |
3/4-14NPTC-3 |
- |
- |
1.0648 |
3/4-14NPTC-4 |
- |
- |
1.0893 |
1 |
11-1/2 |
1.2563 |
1.2658 |
- |
1-1/2 |
11-1/2 |
1.613 |
- |
- |
1-1/2 |
11-1/2 |
1.8413 |
- |
- |
2 |
11-1/2 |
2.3163 |
- |
- |
2-1/2 |
8 |
2.7906 |
- |
- |
3 |
8 |
3.4156 |
- |
- |
* 3-1/2 |
8 |
3.9156 |
- |
- |
* 4 |
8 |
4.4156 |
- |
- |
Length specification Table for NPT, ANPT, NPTF, NPTR, NPTG and NPTC pipe threads
Pipe
Size |
Threads
Per.
inch |
Pitch |
Handtight
Engaged
|
Effective Thread Length |
NPT
ANPT
NPTF |
NPTR |
NPTG
NPTC |
1/16 |
27 |
.0370 |
.16 |
.2611 |
- |
- |
1/8 |
27 |
.0370 |
.180 |
.2639 |
- |
- |
1/4 |
18 |
.0556 |
.200 |
.4018 |
- |
- |
3/8 |
18 |
.0556 |
.240 |
.4078 |
- |
- |
1/2 |
14 |
.0714 |
.320 |
.5337 |
.320 |
.6771 |
3/4 |
14 |
.0714 |
.339 |
.5457 |
.332 |
.6964 |
3/4-14NPTC-1 |
.0714 |
.339 |
- |
- |
.9461 |
3/4-14NPTC-2 |
.0714 |
.339 |
- |
- |
.9461 |
3/4-14NPTC-3 |
.0714 |
.339 |
- |
- |
.9461 |
3/4-14NPTC-4 |
.0714 |
.339 |
- |
- |
.9461 |
1 |
11-1/2 |
0.870 |
.400 |
.6828 |
.422 |
.8348 |
1-1/2 |
11-1/2 |
0.870 |
.420 |
.7068 |
.446 |
- |
1-1/2 |
11-1/2 |
0.870 |
.420 |
.7235 |
.463 |
- |
2 |
11-1/2 |
0.870 |
.436 |
.7565 |
.496 |
- |
2-1/2 |
8 |
.1250 |
.682 |
1.1375 |
.638 |
- |
3 |
8 |
.1250 |
.766 |
1.2000 |
.700 |
- |
* 3-1/2 |
8 |
.1250 |
.821 |
1.2500 |
.750 |
- |
* 4 |
8 |
.1250 |
.844 |
1.3000 |
.800 |
- |
Mechanical Tolerances for Taper Pipe Threads

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