Technical Data
Standards, threads and pressure ratings.
Reference data for TSP malleable iron pipe fittings, transcribed from our published product catalogues. Values below are standard-level and family-level — they describe the standard a product family is built to, not a measured value for an individual item.
Per-size dimensional and unit-weight data is not included on this page. Contact TSP for product-specific technical information.
Standard framework by family
| Family | Design | Thread | Material | Zinc coating | Reinforcement |
|---|---|---|---|---|---|
| American | ANSI/ASME B16.3, B16.14, B16.39 | ANSI/ASME B1.20.1 | ASTM A197 | ASTM A153 | Banded |
| European | EN 10242 | ISO 7-1 | EN 1562 | EN 10242 | Beaded |
| British | BS 143 & 1256 | BS 21 | BS EN 1562 | BS 143 & 1256 | Banded |
| Japanese | JIS B 2301 | JIS B 0203 / JIS B 0202 | JIS G 5702 | JIS B 2301 | Banded / Plain |
This is the framework TSP manufactures to. It does not mean every product complies with every standard. Applicable standards vary by product and family — confirm the applicable specification on the product documentation or with TSP before specification or ordering.
Pressure–temperature ratings (standard / family level)
American family — Class 150
| Service temperature (°C) | Maximum working pressure (bar) |
|---|---|
| −29 to 66 | 20.7 |
| 100 | 17.5 |
| 125 | 15.2 |
| 150 | 12.8 |
| 175 | 10.5 |
American family — Class 300
| Service temperature (°C) | ¼–1″ (bar) | 1¼–2″ (bar) | 2½–3″ (bar) |
|---|---|---|---|
| −29 to 66 | 137.9 | 103.4 | 69.0 |
| 100 | 119.6 | 90.5 | 61.5 |
| 125 | 106.4 | 81.1 | 56.1 |
| 150 | 93.1 | 71.8 | 50.7 |
| 175 | 79.9 | 62.5 | 45.2 |
| 200 | 66.6 | 53.1 | 39.8 |
| 225 | 53.4 | 43.8 | 34.3 |
| 250 | 40.1 | 34.5 | 28.9 |
| 275 | 26.9 | 25.2 | 23.4 |
| 288 | 20.7 | 20.7 | 20.7 |
European family — EN 10242
| Service temperature (°C) | Maximum permissible working pressure (bar) |
|---|---|
| −20 to 120 | 25 |
| Above 300 | 20 |
Between 120 °C and 300 °C the permissible pressure is interpolated between these two points, as stated in the catalogue. These are standard-level ratings for the fitting under the referenced standard, not individual product ratings. System design remains the responsibility of the specifier.
Thread specifications (standard level)
NPT taper thread — ANSI/ASME B1.20.1 (inches)
| Size | OD | Threads/inch | Pitch | Thread height | Hand-tight length | Hand-tight dia. | Effective thread length |
|---|---|---|---|---|---|---|---|
| 1/8 | 0.405 | 27.0 | 0.03704 | 0.02963 | 0.1615 | 0.37360 | 0.2639 |
| 1/4 | 0.540 | 18.0 | 0.05556 | 0.04444 | 0.2278 | 0.49163 | 0.4018 |
| 3/8 | 0.675 | 18.0 | 0.05556 | 0.04444 | 0.2400 | 0.62701 | 0.4078 |
| 1/2 | 0.840 | 14.0 | 0.07143 | 0.05714 | 0.3200 | 0.77843 | 0.5337 |
| 3/4 | 1.050 | 14.0 | 0.07143 | 0.05714 | 0.3390 | 0.98887 | 0.5457 |
| 1 | 1.315 | 11.5 | 0.08696 | 0.06957 | 0.4000 | 1.23863 | 0.6828 |
| 1 1/4 | 1.660 | 11.5 | 0.08696 | 0.06957 | 0.4200 | 1.58338 | 0.7068 |
| 1 1/2 | 1.900 | 11.5 | 0.08696 | 0.06957 | 0.4200 | 1.82234 | 0.7235 |
| 2 | 2.375 | 11.5 | 0.08696 | 0.06957 | 0.4360 | 2.29627 | 0.7565 |
| 2 1/2 | 2.875 | 8.0 | 0.12500 | 0.10000 | 0.6820 | 2.76216 | 1.1375 |
| 3 | 3.500 | 8.0 | 0.12500 | 0.10000 | 0.7660 | 3.38850 | 1.2000 |
| 3 1/2 | 4.000 | 8.0 | 0.12500 | 0.10000 | 0.8210 | 3.88881 | 1.2500 |
| 4 | 4.500 | 8.0 | 0.12500 | 0.10000 | 0.8440 | 4.38712 | 1.3000 |
| 5 | 5.563 | 8.0 | 0.12500 | 0.10000 | 0.9370 | 5.44929 | 1.4063 |
| 6 | — | 8.0 | 0.12500 | 0.10000 | 0.9580 | 6.50597 | 1.5125 |
Tolerance on gauge-plane position is ±1 turn, external and internal, across all sizes. The 6″ outside diameter is withheld pending confirmation against the master catalogue.
ISO 7-1 parallel thread — European family (millimetres)
| Size | DN | Pitch P | Turns / 25.4 mm | Major d | Pitch d2 | Minor d1 | Gauge length max/nom/min | Useful thread max/nom/min |
|---|---|---|---|---|---|---|---|---|
| 1/8 | 4 | 0.907 | 28 | 9.728 | 9.147 | 8.566 | 7.4 / 6.5 / 5.6 | 4.9 / 4.0 / 3.1 |
| 1/4 | 8 | 1.337 | 19 | 13.157 | 12.301 | 11.445 | 11.0 / 9.7 / 8.4 | 7.3 / 6.0 / 4.7 |
| 3/8 | 10 | 1.337 | 19 | 16.662 | 15.806 | 14.950 | 11.4 / 10.1 / 8.8 | 7.7 / 6.4 / 5.1 |
| 1/2 | 15 | 1.814 | 14 | 20.955 | 19.793 | 18.631 | 15.0 / 13.2 / 11.4 | 10.0 / 8.2 / 6.4 |
| 3/4 | 20 | 1.814 | 14 | 26.441 | 25.279 | 24.117 | 16.3 / 14.5 / 12.7 | 11.3 / 9.5 / 7.7 |
| 1 | 25 | 2.309 | 11 | 33.249 | 31.770 | 30.291 | 19.1 / 16.8 / 14.5 | 12.7 / 10.4 / 8.1 |
| 1 1/4 | 32 | 2.309 | 11 | 41.910 | 40.431 | 38.952 | 21.4 / 19.1 / 16.8 | 15.0 / 12.7 / 10.4 |
| 1 1/2 | 40 | 2.309 | 11 | 47.803 | 46.324 | 44.845 | 21.4 / 19.1 / 16.8 | 15.0 / 12.7 / 10.4 |
| 2 | 50 | 2.309 | 11 | 59.614 | 58.135 | 56.656 | 25.7 / 23.4 / 21.1 | 18.2 / 15.9 / 13.6 |
| 2 1/2 | 65 | 2.309 | 11 | 75.184 | 73.705 | 72.226 | 30.2 / 26.7 / 23.2 | 21.0 / 17.5 / 14.0 |
| 3 | 80 | 2.309 | 11 | 87.884 | 86.405 | 84.926 | 33.3 / 29.8 / 26.3 | 24.1 / 20.6 / 17.1 |
| 4 | 100 | 2.309 | 11 | 113.030 | 111.551 | 110.072 | 39.3 / 35.8 / 32.3 | 28.9 / 25.4 / 21.9 |
| 5 | 125 | 2.309 | 11 | 138.430 | 136.951 | 135.472 | 43.6 / 40.1 / 36.6 | 32.1 / 28.6 / 25.1 |
| 6 | 150 | 2.309 | 11 | 163.830 | 162.351 | 160.872 | 43.6 / 40.1 / 36.6 | 32.1 / 28.6 / 25.1 |
Thread form constants: H = 0.960491 P, h = 0.640327 P. Gauge-plane tolerance ±1 turn to 2″, ±1½ turns from 2½″ upward. European family material is EN 1562 blackheart malleable cast iron, Grade A.