derived_fields listlengths 1 3 | disagreements listlengths 1 3 ⌀ | governing_standard stringclasses 3
values | id stringlengths 1 14 | major_diameter_mm stringlengths 3 8 | minor_diameter_mm stringlengths 4 7 ⌀ | nominal_size stringlengths 1 14 | source stringclasses 7
values | source_quote stringlengths 15 1.91k | thread_angle_degrees stringclasses 2
values | thread_pitch_mm stringclasses 11
values | thread_standard stringclasses 4
values | threads_per_inch stringclasses 9
values | url stringlengths 64 77 | verified_fields listlengths 1 5 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | [
{
"field": "major_diameter_mm",
"versions": [
{
"as_of": "2026-08-12T00:00:00",
"source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx",
"source_quote": "1 | 11 | 2.309 | 1.479 | 33.249 | 31.770 | 30.291 |",
"value": "33.249"
},
{
"as_of": "202... | ISO 228-1 | 1 | 33.249 | 30.291 | 1 | https://amesweb.info/Screws/BSP-Thread-Chart.aspx | 1 | 11 | 2.309 | 1.479 | 33.249 | 31.770 | 30.291 | | 55 | 2.309 | BSP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/1/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
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[
"governing_standard",
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{
"field": "major_diameter_mm",
"versions": [
{
"as_of": "2026-08-12T00:00:00",
"source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx",
"source_quote": "1½ | 11 | 2.309 | 1.479 | 47.803 | 46.324 | 44.845 |",
"value": "47.803"
},
{
"as_of": "20... | ISO 228-1 | 1-1-2 | 47.803 | 44.845 | 1-1/2 | https://amesweb.info/Screws/BSP-Thread-Chart.aspx | 1½ | 11 | 2.309 | 1.479 | 47.803 | 46.324 | 44.845 | | 55 | 2.309 | BSP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/1-1-2/ | [
"major_diameter_mm",
"minor_diameter_mm",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ASME B1.20.1 | 1-1-2-2 | 48.2600 | null | 1-1/2 | https://en.wikipedia.org/wiki/National_pipe_thread | 1.900 | 48.2600 | | 60 | 2.2087 | NPT | 11 1/2 | https://referencesource.org/plumbing-fitting-thread-standards/1-1-2-2/ | [
"major_diameter_mm"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 7-1 | 1-1-2-2-2 | 47.80 | 44.85 | 1 1/2 | https://www.machiningdoctor.com/charts/bsp/ | <https://www.machiningdoctor.com/threadinfo-bspt/?tid=4538> BSPT Rp 1 1/2 | 1 1/2" | 11 | 2.309 | 12.7 | 0 | 47.80 | 46.32 | 44.85 | 0.180 | 45.0 | Rp | <https://www.machiningdoctor.com/threadinfo-bspt/?tid=4539> BSPT Rp 2 | 2" | 11 | 2.309 | 15.9 | 0 | 59.61 | 58.14 | 56.66 | 0.180 | 56.4 | Rp | <https://www.machining... | 55 | 2.309 | BSPT | 11 | https://referencesource.org/plumbing-fitting-thread-standards/1-1-2-2-2/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 1-1-2-3 | 47.803 | 44.846 | 1 1/2 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 1 1/2 | 1 1/2" | 11 | 2.309 | 47.803 | 46.324 | 44.846 | 55 | 2.309 | BSPP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/1-1-2-3/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"thread_standard"
] | null | null | 1-1-2-inch-bsp | 47.80 | null | 1-1/2 Inch BSP | https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained | 1-1/2 Inch BSP | 47.80 mm | 45.5 mm | 11 | null | null | BSP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/1-1-2-inch-bsp/ | [
"major_diameter_mm",
"nominal_size",
"threads_per_inch"
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[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
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{
"field": "major_diameter_mm",
"versions": [
{
"as_of": "2026-08-12T00:00:00",
"source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx",
"source_quote": "1¼ | 11 | 2.309 | 1.479 | 41.910 | 40.431 | 38.952 |",
"value": "41.910"
},
{
"as_of": "20... | ISO 228-1 | 1-1-4 | 41.910 | 38.952 | 1-1/4 | https://amesweb.info/Screws/BSP-Thread-Chart.aspx | 1¼ | 11 | 2.309 | 1.479 | 41.910 | 40.431 | 38.952 | | 55 | 2.309 | BSP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/1-1-4/ | [
"major_diameter_mm",
"minor_diameter_mm",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ASME B1.20.1 | 1-1-4-2 | 42.1640 | null | 1-1/4 | https://en.wikipedia.org/wiki/National_pipe_thread | 1.660 | 42.1640 | | 60 | 2.2087 | NPT | 11 1/2 | https://referencesource.org/plumbing-fitting-thread-standards/1-1-4-2/ | [
"major_diameter_mm"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 7-1 | 1-1-4-2-2 | 41.91 | 38.95 | 1 1/4 | https://www.machiningdoctor.com/charts/bsp/ | <https://www.machiningdoctor.com/threadinfo-bspt/?tid=4537> BSPT Rp 1 1/4 | 1 1/4" | 11 | 2.309 | 12.7 | 0 | 41.91 | 40.43 | 38.95 | 0.180 | 39.0 | Rp | <https://www.machiningdoctor.com/threadinfo-bspt/?tid=4538> BSPT Rp 1 1/2 | 1 1/2" | 11 | 2.309 | 12.7 | 0 | 47.80 | 46.32 | 44.85 | 0.180 | 45.0 | Rp | <https://www.m... | 55 | 2.309 | BSPT | 11 | https://referencesource.org/plumbing-fitting-thread-standards/1-1-4-2-2/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 1-1-4-3 | 41.910 | 38.953 | 1 1/4 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 1 1/4 | 1 1/4" | 11 | 2.309 | 41.910 | 40.431 | 38.953 | 55 | 2.309 | BSPP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/1-1-4-3/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"thread_standard"
] | null | null | 1-1-4-inch-bsp | 41.91 | null | 1-1/4 Inch BSP | https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained | 1-1/4 Inch BSP | 41.91 mm | 39.6 mm | 11 | null | null | BSP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/1-1-4-inch-bsp/ | [
"major_diameter_mm",
"nominal_size",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 1-1-8 | 37.897 | 34.939 | 1-1/8 | https://en.wikipedia.org/wiki/British_Standard_Pipe | 1.4920 | 37.897 | 55 | 2.309 | BSP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/1-1-8/ | [
"major_diameter_mm"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 1-1-8-2 | 37.897 | 34.940 | 1 1/8 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 1 1/8 | 1 1/8" | 11 | 2.309 | 37.897 | 36.418 | 34.940 | 55 | 2.309 | BSPP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/1-1-8-2/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 1-10 | 33.249 | 30.292 | 1 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 1 | 1" | 11 | 2.309 | 33.249 | 31.770 | 30.292 | 55 | 2.309 | BSPP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/1-10/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 1-16 | 7.723 | 6.561 | 1/16 | https://amesweb.info/Screws/BSP-Thread-Chart.aspx | 1/16 | 28 | 0.907 | 0.581 | 7.723 | 7.142 | 6.561 | | 55 | 0.907 | BSP | 28 | https://referencesource.org/plumbing-fitting-thread-standards/1-16/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ASME B1.20.1 | 1-16-2 | 7.950 | null | 1/16 | https://en.wikipedia.org/wiki/National_pipe_thread | 0.313 | 7.950 | | 60 | 0.9407 | NPT | 27 | https://referencesource.org/plumbing-fitting-thread-standards/1-16-2/ | [
"major_diameter_mm"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 7-1 | 1-16-2-2 | 7.72 | 6.56 | 1/16 | https://www.machiningdoctor.com/charts/bsp/ | 111.55 | 110.07 | 0 | -999.00 | R | <https://www.machiningdoctor.com/threadinfo-bspt/?tid=4513> BSPT R 5 | 5" | 11 | 2.309 | 28.6 | 1.5 / 3.5 | 138.43 | 136.95 | 135.47 | 0 | -999.00 | R | <https://www.machiningdoctor.com/threadinfo-bspt/?tid=4514> BSPT R 6 | 6" | 11 | 2.309 | 28.6 | 1.5 / 3.5 | 163.83 | 162.35 | 160.8... | 55 | 0.907 | BSPT | 28 | https://referencesource.org/plumbing-fitting-thread-standards/1-16-2-2/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 1-16-3 | 7.723 | 6.561 | 1/16 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 1/16 | 1/16" | 28 | 0.907 | 7.723 | 7.142 | 6.561 | 55 | 0.907 | BSPP | 28 | https://referencesource.org/plumbing-fitting-thread-standards/1-16-3/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | [
{
"field": "major_diameter_mm",
"versions": [
{
"as_of": "2026-08-12T00:00:00",
"source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx",
"source_quote": "1/2 | 14 | 1.814 | 1.162 | 20.955 | 19.793 | 18.631 |",
"value": "20.955"
},
{
"as_of": "2... | ISO 228-1 | 1-2 | 20.955 | 18.631 | 1/2 | https://amesweb.info/Screws/BSP-Thread-Chart.aspx | 1/2 | 14 | 1.814 | 1.162 | 20.955 | 19.793 | 18.631 | | 55 | 1.814 | BSP | 14 | https://referencesource.org/plumbing-fitting-thread-standards/1-2/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | [
{
"field": "thread_pitch_mm",
"versions": [
{
"as_of": "2026-08-12T00:00:00",
"source": "https://en.wikipedia.org/wiki/National_pipe_thread",
"source_quote": "0.840 | 21.3360 |",
"value": "1.8143"
},
{
"as_of": "2026-08-12T00:00:00",
"source"... | ASME B1.20.1 | 1-2-2 | 21.3360 | null | 1/2 | https://en.wikipedia.org/wiki/National_pipe_thread | 0.840 | 21.3360 | | 60 | 1.8143 | NPT | 14 | https://referencesource.org/plumbing-fitting-thread-standards/1-2-2/ | [
"major_diameter_mm"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 7-1 | 1-2-2-3 | 20.96 | 18.63 | 1/2 | https://www.machiningdoctor.com/charts/bsp/ | 20.96 | 19.79 | 18.63 | 0.142 | 18.5 | Rp | <https://www.machiningdoctor.com/threadinfo-bspt/?tid=4535> BSPT Rp 3/4 | 3/4" | 14 | 1.814 | 9.5 | 0 | 26.44 | 25.28 | 24.12 | 0.142 | 24.0 | Rp | <https://www.machiningdoctor.com/threadinfo-bspt/?tid=4536> BSPT Rp 1 | 1" | 11 | 2.309 | 10.4 | 0 | 33.25 | 31.77 | 30.29 | 0.1... | 55 | 1.814 | BSPT | 14 | https://referencesource.org/plumbing-fitting-thread-standards/1-2-2-3/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 1-2-4 | 20.955 | 18.632 | 1/2 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 1/2 | 1/2" | 14 | 1.814 | 20.955 | 19.793 | 18.632 | 55 | 1.814 | BSPP | 14 | https://referencesource.org/plumbing-fitting-thread-standards/1-2-4/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"thread_standard"
] | null | null | 1-2-inch-bsp | 20.99 | null | 1/2 Inch BSP | https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained | 1/2 Inch BSP | 20.99 mm | 19.1 mm | 14 | null | null | BSP | 14 | https://referencesource.org/plumbing-fitting-thread-standards/1-2-inch-bsp/ | [
"major_diameter_mm",
"nominal_size",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | [
{
"field": "threads_per_inch",
"versions": [
{
"as_of": "2026-08-12T00:00:00",
"source": "https://en.wikipedia.org/wiki/National_pipe_thread",
"source_quote": "1.315 | 33.4010 |",
"value": "11 1/2"
},
{
"as_of": "2026-08-12T00:00:00",
"source... | ASME B1.20.1 | 1-3 | 33.4010 | null | 1 | https://en.wikipedia.org/wiki/National_pipe_thread | 1.315 | 33.4010 | | 60 | 2.2087 | NPT | 11 1/2 | https://referencesource.org/plumbing-fitting-thread-standards/1-3/ | [
"major_diameter_mm",
"nominal_size"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ASME B1.20.1 | 1-3-2 | 42.16 | null | 1¼ | https://www.geminivalve.com/bsp-thread-vs-npt-fitting/ | 1¼ | 11½ | 0.08696 | 2.20878 | 1.66 | 42.16 | 60 | 2.20878 | NPT | 11½ | https://referencesource.org/plumbing-fitting-thread-standards/1-3-2/ | [
"major_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 1-3-4 | 53.746 | 50.789 | 1 3/4 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 1 3/4 | 1 3/4" | 11 | 2.309 | 53.746 | 52.267 | 50.789 | 55 | 2.309 | BSPP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/1-3-4/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | [
{
"field": "major_diameter_mm",
"versions": [
{
"as_of": "2026-08-12T00:00:00",
"source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx",
"source_quote": "1/4 | 19 | 1.337 | 0.856 | 13.157 | 12.301 | 11.445 |",
"value": "13.157"
},
{
"as_of": "2... | ISO 228-1 | 1-4 | 13.157 | 11.445 | 1/4 | https://amesweb.info/Screws/BSP-Thread-Chart.aspx | 1/4 | 19 | 1.337 | 0.856 | 13.157 | 12.301 | 11.445 | | 55 | 1.337 | BSP | 19 | https://referencesource.org/plumbing-fitting-thread-standards/1-4/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | [
{
"field": "thread_pitch_mm",
"versions": [
{
"as_of": "2026-08-12T00:00:00",
"source": "https://en.wikipedia.org/wiki/National_pipe_thread",
"source_quote": "0.540 | 13.716 |",
"value": "1.4111"
},
{
"as_of": "2026-08-12T00:00:00",
"source":... | ASME B1.20.1 | 1-4-2 | 13.716 | null | 1/4 | https://en.wikipedia.org/wiki/National_pipe_thread | 0.540 | 13.716 | | 60 | 1.4111 | NPT | 18 | https://referencesource.org/plumbing-fitting-thread-standards/1-4-2/ | [
"major_diameter_mm"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 7-1 | 1-4-2-3 | 13.16 | 11.45 | 1/4 | https://www.machiningdoctor.com/charts/bsp/ | 13.16 | 12.30 | 11.45 | 0.104 | 11.5 | Rp | <https://www.machiningdoctor.com/threadinfo-bspt/?tid=4533> BSPT Rp 3/8 | 3/8" | 19 | 1.337 | 6.4 | 0 | 16.66 | 15.81 | 14.95 | 0.104 | 15.0 | Rp | <https://www.machiningdoctor.com/threadinfo-bspt/?tid=4534> BSPT Rp 1/2 | 1/2" | 14 | 1.814 | 8.2 | 0 | 20.96 | 19.79 | 18.63 | ... | 55 | 1.337 | BSPT | 19 | https://referencesource.org/plumbing-fitting-thread-standards/1-4-2-3/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 1-4-4 | 13.157 | 11.445 | 1/4 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 1/4 | 1/4" | 19 | 1.337 | 13.157 | 12.301 | 11.445 | 55 | 1.337 | BSPP | 19 | https://referencesource.org/plumbing-fitting-thread-standards/1-4-4/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"thread_standard"
] | null | null | 1-4-inch-bsp | 13.16 | null | 1/4 Inch BSP | https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained | 1/4 Inch BSP | 13.16 mm | 11.9mm | 19 | null | null | BSP | 19 | https://referencesource.org/plumbing-fitting-thread-standards/1-4-inch-bsp/ | [
"major_diameter_mm",
"nominal_size",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ASME B1.20.1 | 1-5 | 48.26 | null | 1½ | https://www.geminivalve.com/bsp-thread-vs-npt-fitting/ | 1½ | 11½ | 0.08695 | 2.20878 | 1.9 | 48.26 | 60 | 2.20878 | NPT | 11½ | https://referencesource.org/plumbing-fitting-thread-standards/1-5/ | [
"major_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 1-7 | 41.91 | 38.953 | 1¼ | https://www.geminivalve.com/bsp-thread-vs-npt-fitting/ | 1¼ | 11 | 0.0909 | 2.309 | 1.65 | 41.91 | 1.5336 | 38.953 | 0.5 | 12.7 | 55 | 2.309 | BSP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/1-7/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | [
{
"field": "major_diameter_mm",
"versions": [
{
"as_of": "2026-08-12T00:00:00",
"source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx",
"source_quote": "1/8 | 28 | 0.907 | 0.581 | 9.728 | 9.147 | 8.566 |",
"value": "9.728"
},
{
"as_of": "2026-... | ISO 228-1 | 1-8 | 9.728 | 8.566 | 1/8 | https://amesweb.info/Screws/BSP-Thread-Chart.aspx | 1/8 | 28 | 0.907 | 0.581 | 9.728 | 9.147 | 8.566 | | 55 | 0.907 | BSP | 28 | https://referencesource.org/plumbing-fitting-thread-standards/1-8/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
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"thread_standard"
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{
"field": "thread_pitch_mm",
"versions": [
{
"as_of": "2026-08-12T00:00:00",
"source": "https://en.wikipedia.org/wiki/National_pipe_thread",
"source_quote": "0.405 | 10.287 |",
"value": "0.9407"
},
{
"as_of": "2026-08-12T00:00:00",
"source":... | ASME B1.20.1 | 1-8-2 | 10.287 | null | 1/8 | https://en.wikipedia.org/wiki/National_pipe_thread | 0.405 | 10.287 | | 60 | 0.9407 | NPT | 27 | https://referencesource.org/plumbing-fitting-thread-standards/1-8-2/ | [
"major_diameter_mm"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 7-1 | 1-8-2-3 | 9.73 | 8.57 | 1/8 | https://www.machiningdoctor.com/charts/bsp/ | 111.55 | 110.07 | 0 | -999.00 | R | <https://www.machiningdoctor.com/threadinfo-bspt/?tid=4513> BSPT R 5 | 5" | 11 | 2.309 | 28.6 | 1.5 / 3.5 | 138.43 | 136.95 | 135.47 | 0 | -999.00 | R | <https://www.machiningdoctor.com/threadinfo-bspt/?tid=4514> BSPT R 6 | 6" | 11 | 2.309 | 28.6 | 1.5 / 3.5 | 163.83 | 162.35 | 160.8... | 55 | 0.907 | BSPT | 28 | https://referencesource.org/plumbing-fitting-thread-standards/1-8-2-3/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 1-8-4 | 9.728 | 8.566 | 1/8 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 1/8 | 1/8" | 28 | 0.907 | 9.728 | 9.147 | 8.566 | 55 | 0.907 | BSPP | 28 | https://referencesource.org/plumbing-fitting-thread-standards/1-8-4/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"thread_standard"
] | null | null | 1-8-inch-bsp | 9.7 | null | 1/8 Inch BSP | https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained | 1/8 Inch BSP | 9.7 mm | 8.9 mm | 28 | null | null | BSP | 28 | https://referencesource.org/plumbing-fitting-thread-standards/1-8-inch-bsp/ | [
"major_diameter_mm",
"nominal_size",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 1-9 | 46.803 | 44.846 | 1½ | https://www.geminivalve.com/bsp-thread-vs-npt-fitting/ | 1½ | 11 | 0.0909 | 2.309 | 1.882 | 46.803 | 1.7656 | 44.846 | 0.5 | 12.7 | 55 | 2.309 | BSP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/1-9/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"thread_standard"
] | null | null | 1-inch-bsp | 33.25 | null | 1 Inch BSP | https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained | 1 Inch BSP | 33.25 mm | 31.0 mm | 11 | null | null | BSP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/1-inch-bsp/ | [
"major_diameter_mm",
"nominal_size",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ASME B1.20.1 | 10 | 273.0500 | null | 10 | https://en.wikipedia.org/wiki/National_pipe_thread | 10.750 | 273.0500 | | 60 | 3.1750 | NPT | 8 | https://referencesource.org/plumbing-fitting-thread-standards/10/ | [
"major_diameter_mm",
"nominal_size"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ASME B1.20.1 | 12 | 323.8500 | null | 12 | https://en.wikipedia.org/wiki/National_pipe_thread | 12.750 | 323.8500 | | 60 | 3.1750 | NPT | 8 | https://referencesource.org/plumbing-fitting-thread-standards/12/ | [
"major_diameter_mm",
"nominal_size"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | [
{
"field": "major_diameter_mm",
"versions": [
{
"as_of": "2026-08-12T00:00:00",
"source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx",
"source_quote": "2 | 11 | 2.309 | 1.479 | 59.614 | 58.135 | 56.656 |",
"value": "59.614"
},
{
"as_of": "202... | ISO 228-1 | 2 | 59.614 | 56.656 | 2 | https://amesweb.info/Screws/BSP-Thread-Chart.aspx | 2 | 11 | 2.309 | 1.479 | 59.614 | 58.135 | 56.656 | | 55 | 2.309 | BSP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/2/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 2-1-2 | 75.184 | 72.226 | 2-1/2 | https://amesweb.info/Screws/BSP-Thread-Chart.aspx | 2½ | 11 | 2.309 | 1.479 | 75.184 | 73.705 | 72.226 | | 55 | 2.309 | BSP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/2-1-2/ | [
"major_diameter_mm",
"minor_diameter_mm",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ASME B1.20.1 | 2-1-2-2 | 73.0250 | null | 2-1/2 | https://en.wikipedia.org/wiki/National_pipe_thread | 2.875 | 73.0250 | | 60 | 3.1750 | NPT | 8 | https://referencesource.org/plumbing-fitting-thread-standards/2-1-2-2/ | [
"major_diameter_mm"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 7-1 | 2-1-2-2-2 | 75.18 | 72.23 | 2 1/2 | https://www.machiningdoctor.com/charts/bsp/ | <https://www.machiningdoctor.com/threadinfo-bspt/?tid=4540> BSPT Rp 2 1/2 | 2 1/2" | 11 | 2.309 | 17.5 | 0 | 75.18 | 73.71 | 72.23 | 0.216 | -999 | Rp | <https://www.machiningdoctor.com/threadinfo-bspt/?tid=4541> BSPT Rp 3 | 3" | 11 | 2.309 | 20.6 | 0 | 87.88 | 86.41 | 84.93 | 0.216 | -999 | Rp | <https://www.machining... | 55 | 2.309 | BSPT | 11 | https://referencesource.org/plumbing-fitting-thread-standards/2-1-2-2-2/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 2-1-2-3 | 75.184 | 72.227 | 2 1/2 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 2 1/2 | 2 1/2" | 11 | 2.309 | 75.184 | 73.705 | 72.227 | 55 | 2.309 | BSPP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/2-1-2-3/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 2-1-4 | 65.710 | 62.753 | 2 1/4 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 2 1/4 | 2 1/4" | 11 | 2.309 | 65.710 | 64.231 | 62.753 | 55 | 2.309 | BSPP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/2-1-4/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | [
{
"field": "threads_per_inch",
"versions": [
{
"as_of": "2026-08-12T00:00:00",
"source": "https://en.wikipedia.org/wiki/National_pipe_thread",
"source_quote": "2.375 | 60.3250 |",
"value": "11 1/2"
},
{
"as_of": "2026-08-12T00:00:00",
"source... | ASME B1.20.1 | 2-2 | 60.3250 | null | 2 | https://en.wikipedia.org/wiki/National_pipe_thread | 2.375 | 60.3250 | | 60 | 2.2087 | NPT | 11 1/2 | https://referencesource.org/plumbing-fitting-thread-standards/2-2/ | [
"major_diameter_mm",
"nominal_size"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ASME B1.20.1 | 2-2-2 | 73.03 | null | 2½ | https://www.geminivalve.com/bsp-thread-vs-npt-fitting/ | 2½ | 8 | 0.125 | 3.175 | 2.875 | 73.03 | 60 | 3.175 | NPT | 8 | https://referencesource.org/plumbing-fitting-thread-standards/2-2-2/ | [
"major_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 2-3-4 | 81.534 | 78.577 | 2 3/4 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 2 3/4 | 2 3/4" | 11 | 2.309 | 81.534 | 80.055 | 78.577 | 55 | 2.309 | BSPP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/2-3-4/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 2-4 | 75.184 | 72.227 | 2½ | https://www.geminivalve.com/bsp-thread-vs-npt-fitting/ | 2½ | 11 | 0.0909 | 2.309 | 2.96 | 75.184 | 2.8436 | 72.227 | 0.6875 | 17.463 | 55 | 2.309 | BSP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/2-4/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 2-5 | 59.614 | 56.657 | 2 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 2 | 2" | 11 | 2.309 | 59.614 | 58.135 | 56.657 | 55 | 2.309 | BSPP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/2-5/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"thread_standard"
] | null | null | 2-inch-bsp | 59.61 | null | 2 Inch BSP | https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained | 2 Inch BSP | 59.61 mm | 57.4 mm | 11 | null | null | BSP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/2-inch-bsp/ | [
"major_diameter_mm",
"nominal_size",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | [
{
"field": "minor_diameter_mm",
"versions": [
{
"as_of": "2026-08-12T00:00:00",
"source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx",
"source_quote": "3 | 11 | 2.309 | 1.479 | 87.884 | 86.405 | 84.926 |",
"value": "84.926"
},
{
"as_of": "202... | ISO 228-1 | 3 | 87.884 | 84.926 | 3 | https://amesweb.info/Screws/BSP-Thread-Chart.aspx | 3 | 11 | 2.309 | 1.479 | 87.884 | 86.405 | 84.926 | | 55 | 2.309 | BSP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/3/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ASME B1.20.1 | 3-1-2 | 101.6000 | null | 3-1/2 | https://en.wikipedia.org/wiki/National_pipe_thread | 4.000 | 101.6000 | | 60 | 3.1750 | NPT | 8 | https://referencesource.org/plumbing-fitting-thread-standards/3-1-2/ | [
"major_diameter_mm"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 3-1-2-2 | 100.330 | 97.373 | 3 1/2 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 3 1/2 | 3 1/2" | 11 | 2.309 | 100.330 | 98.851 | 97.373 | 55 | 2.309 | BSPP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/3-1-2-2/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | [
{
"field": "thread_pitch_mm",
"versions": [
{
"as_of": "2026-08-12T00:00:00",
"source": "https://en.wikipedia.org/wiki/National_pipe_thread",
"source_quote": "3.500 | 88.9000 |",
"value": "3.1750"
},
{
"as_of": "2026-08-12T00:00:00",
"source"... | ASME B1.20.1 | 3-2 | 88.9000 | null | 3 | https://en.wikipedia.org/wiki/National_pipe_thread | 3.500 | 88.9000 | | 60 | 3.1750 | NPT | 8 | https://referencesource.org/plumbing-fitting-thread-standards/3-2/ | [
"major_diameter_mm",
"nominal_size"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | [
{
"field": "major_diameter_mm",
"versions": [
{
"as_of": "2026-08-12T00:00:00",
"source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx",
"source_quote": "3/4 | 14 | 1.814 | 1.162 | 26.441 | 25.279 | 24.117 |",
"value": "26.441"
},
{
"as_of": "2... | ISO 228-1 | 3-4 | 26.441 | 24.117 | 3/4 | https://amesweb.info/Screws/BSP-Thread-Chart.aspx | 3/4 | 14 | 1.814 | 1.162 | 26.441 | 25.279 | 24.117 | | 55 | 1.814 | BSP | 14 | https://referencesource.org/plumbing-fitting-thread-standards/3-4/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | [
{
"field": "thread_pitch_mm",
"versions": [
{
"as_of": "2026-08-12T00:00:00",
"source": "https://en.wikipedia.org/wiki/National_pipe_thread",
"source_quote": "1.050 | 26.6700 |",
"value": "1.8143"
},
{
"as_of": "2026-08-12T00:00:00",
"source"... | ASME B1.20.1 | 3-4-2 | 26.6700 | null | 3/4 | https://en.wikipedia.org/wiki/National_pipe_thread | 1.050 | 26.6700 | | 60 | 1.8143 | NPT | 14 | https://referencesource.org/plumbing-fitting-thread-standards/3-4-2/ | [
"major_diameter_mm"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 7-1 | 3-4-2-3 | 26.44 | 24.12 | 3/4 | https://www.machiningdoctor.com/charts/bsp/ | <https://www.machiningdoctor.com/threadinfo-bspt/?tid=4505> BSPT R 3/4 | 3/4" | 14 | 1.814 | 9.5 | 1.0 / 1.8 | 26.44 | 25.28 | 24.12 | 0 | -999.00 | R | <https://www.machiningdoctor.com/threadinfo-bspt/?tid=4506> BSPT R 1 | 1" | 11 | 2.309 | 10.4 | 1.0 / 2.3 | 33.25 | 31.77 | 30.29 | 0 | -999.00 | R | <https://www.mach... | 55 | 1.814 | BSPT | 14 | https://referencesource.org/plumbing-fitting-thread-standards/3-4-2-3/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 3-4-4 | 26.441 | 24.118 | 3/4 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 3/4 | 3/4" | 14 | 1.814 | 26.441 | 25.279 | 24.118 | 55 | 1.814 | BSPP | 14 | https://referencesource.org/plumbing-fitting-thread-standards/3-4-4/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"thread_standard"
] | null | null | 3-4-inch-bsp | 26.44 | null | 3/4 Inch BSP | https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained | 3/4 Inch BSP | 26.44 mm | 24.6 mm | 14 | null | null | BSP | 14 | https://referencesource.org/plumbing-fitting-thread-standards/3-4-inch-bsp/ | [
"major_diameter_mm",
"nominal_size",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 3-5 | 87.884 | 84.927 | 3 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 3 | 3" | 11 | 2.309 | 87.884 | 86.405 | 84.927 | 55 | 2.309 | BSPP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/3-5/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | [
{
"field": "major_diameter_mm",
"versions": [
{
"as_of": "2026-08-12T00:00:00",
"source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx",
"source_quote": "3/8 | 19 | 1.337 | 0.856 | 16.662 | 15.806 | 14.950 |",
"value": "16.662"
},
{
"as_of": "2... | ISO 228-1 | 3-8 | 16.662 | 14.950 | 3/8 | https://amesweb.info/Screws/BSP-Thread-Chart.aspx | 3/8 | 19 | 1.337 | 0.856 | 16.662 | 15.806 | 14.950 | | 55 | 1.337 | BSP | 19 | https://referencesource.org/plumbing-fitting-thread-standards/3-8/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | [
{
"field": "thread_pitch_mm",
"versions": [
{
"as_of": "2026-08-12T00:00:00",
"source": "https://en.wikipedia.org/wiki/National_pipe_thread",
"source_quote": "0.675 | 17.145 |",
"value": "1.4111"
},
{
"as_of": "2026-08-12T00:00:00",
"source":... | ASME B1.20.1 | 3-8-2 | 17.145 | null | 3/8 | https://en.wikipedia.org/wiki/National_pipe_thread | 0.675 | 17.145 | | 60 | 1.4111 | NPT | 18 | https://referencesource.org/plumbing-fitting-thread-standards/3-8-2/ | [
"major_diameter_mm"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 7-1 | 3-8-2-3 | 16.66 | 14.95 | 3/8 | https://www.machiningdoctor.com/charts/bsp/ | <https://www.machiningdoctor.com/threadinfo-bspt/?tid=4503> BSPT R 3/8 | 3/8" | 19 | 1.337 | 6.4 | 1.0 / 1.3 | 16.66 | 15.81 | 14.95 | | 55 | 1.337 | BSPT | 19 | https://referencesource.org/plumbing-fitting-thread-standards/3-8-2-3/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 3-8-4 | 16.662 | 14.950 | 3/8 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 3/8 | 3/8" | 19 | 1.337 | 16.662 | 15.806 | 14.950 | 55 | 1.337 | BSPP | 19 | https://referencesource.org/plumbing-fitting-thread-standards/3-8-4/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"thread_standard"
] | null | null | 3-8-inch-bsp | 16.66 | null | 3/8 Inch BSP | https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained | 3/8 Inch BSP | 16.66 mm | 15.2 mm | 19 | null | null | BSP | 19 | https://referencesource.org/plumbing-fitting-thread-standards/3-8-inch-bsp/ | [
"major_diameter_mm",
"nominal_size",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | [
{
"field": "major_diameter_mm",
"versions": [
{
"as_of": "2026-08-12T00:00:00",
"source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx",
"source_quote": "4 | 11 | 2.309 | 1.479 | 113.030 | 111.551 | 110.072 |",
"value": "113.030"
},
{
"as_of": ... | ISO 228-1 | 4 | 113.030 | 110.072 | 4 | https://amesweb.info/Screws/BSP-Thread-Chart.aspx | 4 | 11 | 2.309 | 1.479 | 113.030 | 111.551 | 110.072 | | 55 | 2.309 | BSP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/4/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 4-1-2 | 125.730 | 122.773 | 4 1/2 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 4 1/2 | 4 1/2" | 11 | 2.309 | 125.730 | 124.251 | 122.773 | 55 | 2.309 | BSPP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/4-1-2/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | [
{
"field": "thread_pitch_mm",
"versions": [
{
"as_of": "2026-08-12T00:00:00",
"source": "https://en.wikipedia.org/wiki/National_pipe_thread",
"source_quote": "4.500 | 114.3000 |",
"value": "3.1750"
},
{
"as_of": "2026-08-12T00:00:00",
"source... | ASME B1.20.1 | 4-2 | 114.3000 | null | 4 | https://en.wikipedia.org/wiki/National_pipe_thread | 4.500 | 114.3000 | | 60 | 3.1750 | NPT | 8 | https://referencesource.org/plumbing-fitting-thread-standards/4-2/ | [
"major_diameter_mm",
"nominal_size"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 4-4 | 113.030 | 110.073 | 4 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 4 | 4" | 11 | 2.309 | 113.030 | 111.551 | 110.073 | 55 | 2.309 | BSPP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/4-4/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ASME B1.20.1 | 5 | 141.3002 | null | 5 | https://en.wikipedia.org/wiki/National_pipe_thread | 5.563 | 141.3002 | | 60 | 3.1750 | NPT | 8 | https://referencesource.org/plumbing-fitting-thread-standards/5/ | [
"major_diameter_mm",
"nominal_size"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 5-1-2 | 151.130 | 148.173 | 5 1/2 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 5 1/2 | 5 1/2" | 11 | 2.309 | 151.130 | 149.651 | 148.173 | 55 | 2.309 | BSPP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/5-1-2/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 5-2 | 138.430 | 135.472 | 5 | https://en.wikipedia.org/wiki/British_Standard_Pipe | 5.4500 | 138.430 | 55 | 2.309 | BSP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/5-2/ | [
"major_diameter_mm",
"nominal_size"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 5-3 | 138.430 | 135.473 | 5 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 5 | 5" | 11 | 2.309 | 138.430 | 136.951 | 135.473 | 55 | 2.309 | BSPP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/5-3/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | [
{
"field": "major_diameter_mm",
"versions": [
{
"as_of": "2026-08-12T00:00:00",
"source": "https://en.wikipedia.org/wiki/British_Standard_Pipe",
"source_quote": "0.9020 | 22.911",
"value": "22.911"
},
{
"as_of": "2026-08-12T00:00:00",
"source... | ISO 228-1 | 5-8 | 22.911 | 20.587 | 5/8 | https://en.wikipedia.org/wiki/British_Standard_Pipe | 0.9020 | 22.911 | 55 | 1.814 | BSP | 14 | https://referencesource.org/plumbing-fitting-thread-standards/5-8/ | [
"major_diameter_mm"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 5-8-2 | 22.911 | 20.588 | 5/8 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 5/8 | 5/8" | 14 | 1.814 | 22.911 | 21.749 | 20.588 | 55 | 1.814 | BSPP | 14 | https://referencesource.org/plumbing-fitting-thread-standards/5-8-2/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"thread_standard"
] | null | null | 5-8-inch-bsp | 22.99 | null | 5/8 Inch BSP | https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained | 5/8 Inch BSP | 22.99 mm | 20.3 mm | 14 | null | null | BSP | 14 | https://referencesource.org/plumbing-fitting-thread-standards/5-8-inch-bsp/ | [
"major_diameter_mm",
"nominal_size",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 6 | 163.830 | 160.872 | 6 | https://amesweb.info/Screws/BSP-Thread-Chart.aspx | 6 | 11 | 2.309 | 1.479 | 163.830 | 162.351 | 160.872 | | 55 | 2.309 | BSP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/6/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ASME B1.20.1 | 6-2 | 168.2750 | null | 6 | https://en.wikipedia.org/wiki/National_pipe_thread | 6.625 | 168.2750 | | 60 | 3.1750 | NPT | 8 | https://referencesource.org/plumbing-fitting-thread-standards/6-2/ | [
"major_diameter_mm",
"nominal_size"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 6-3 | 163.830 | 160.873 | 6 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 6 | 6" | 11 | 2.309 | 163.830 | 162.351 | 160.873 | 55 | 2.309 | BSPP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/6-3/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 7-8 | 30.201 | 27.877 | 7/8 | https://en.wikipedia.org/wiki/British_Standard_Pipe | 1.1890 | 30.201 | 55 | 1.814 | BSP | 14 | https://referencesource.org/plumbing-fitting-thread-standards/7-8/ | [
"major_diameter_mm"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 228-1 | 7-8-2 | 30.201 | 27.878 | 7/8 | https://www.machiningdoctor.com/charts/bsp/ | BSPP G 7/8 | 7/8" | 14 | 1.814 | 30.201 | 29.039 | 27.878 | 55 | 1.814 | BSPP | 14 | https://referencesource.org/plumbing-fitting-thread-standards/7-8-2/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ASME B1.20.1 | 8 | 219.0750 | null | 8 | https://en.wikipedia.org/wiki/National_pipe_thread | 8.625 | 219.0750 | | 60 | 3.1750 | NPT | 8 | https://referencesource.org/plumbing-fitting-thread-standards/8/ | [
"major_diameter_mm",
"nominal_size",
"threads_per_inch"
] |
[
"thread_standard"
] | null | null | bsp-1-3 | 41.9 | null | 1 ¼ | https://trimantec.com/blogs/t/thread-identification-guide | -20 (1 ¼) | 11 | 41.9 | 1.65 | 39.6 | 1.56 | null | null | BSP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/bsp-1-3/ | [
"major_diameter_mm",
"nominal_size",
"threads_per_inch"
] |
[
"thread_standard"
] | null | null | bsp-1-5 | 47.8 | null | 1 ½ | https://trimantec.com/blogs/t/thread-identification-guide | -24 (1 ½) | 11 | 47.8 | 1.88 | 45.5 | 1.79 | null | null | BSP | 11 | https://referencesource.org/plumbing-fitting-thread-standards/bsp-1-5/ | [
"major_diameter_mm",
"nominal_size",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 7-1 | bspt-1 | 33.25 | 30.29 | 1 | https://www.machiningdoctor.com/charts/bsp/ | BSPT R 1 | 1" | 11 | 2.309 | 10.4 | 1.0 / 2.3 | 33.25 | 31.77 | 30.29 | 0 | -999.00 | 55 | 2.309 | BSPT | 11 | https://referencesource.org/plumbing-fitting-thread-standards/bspt-1/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 7-1 | bspt-2 | 59.61 | 56.66 | 2 | https://www.machiningdoctor.com/charts/bsp/ | BSPT R 2 | 2" | 11 | 2.309 | 15.9 | 1.0 / 2.3 | 59.61 | 58.14 | 56.66 | 0 | -999.00 | 55 | 2.309 | BSPT | 11 | https://referencesource.org/plumbing-fitting-thread-standards/bspt-2/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 7-1 | bspt-3 | 87.88 | 84.93 | 3 | https://www.machiningdoctor.com/charts/bsp/ | BSPT R 3 | 3" | 11 | 2.309 | 20.6 | 1.5 / 3.5 | 87.88 | 86.41 | 84.93 | 0 | -999.00 | 55 | 2.309 | BSPT | 11 | https://referencesource.org/plumbing-fitting-thread-standards/bspt-3/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 7-1 | bspt-4 | 113.03 | 110.07 | 4 | https://www.machiningdoctor.com/charts/bsp/ | BSPT R 4 | 4" | 11 | 2.309 | 25.4 | 1.5 / 3.5 | 113.03 | 111.55 | 110.07 | 0 | -999.00 | 55 | 2.309 | BSPT | 11 | https://referencesource.org/plumbing-fitting-thread-standards/bspt-4/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 7-1 | bspt-5 | 138.43 | 135.47 | 5 | https://www.machiningdoctor.com/charts/bsp/ | BSPT R 5 | 5" | 11 | 2.309 | 28.6 | 1.5 / 3.5 | 138.43 | 136.95 | 135.47 | 0 | -999.00 | 55 | 2.309 | BSPT | 11 | https://referencesource.org/plumbing-fitting-thread-standards/bspt-5/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"governing_standard",
"thread_angle_degrees",
"thread_standard"
] | null | ISO 7-1 | bspt-6 | 163.83 | 160.87 | 6 | https://www.machiningdoctor.com/charts/bsp/ | BSPT R 6 | 6" | 11 | 2.309 | 28.6 | 1.5 / 3.5 | 163.83 | 162.35 | 160.87 | 0 | -999.00 | 55 | 2.309 | BSPT | 11 | https://referencesource.org/plumbing-fitting-thread-standards/bspt-6/ | [
"major_diameter_mm",
"minor_diameter_mm",
"nominal_size",
"thread_pitch_mm",
"threads_per_inch"
] |
[
"thread_standard"
] | null | null | npt-1-3 | 42.2 | null | 1 ¼ | https://trimantec.com/blogs/t/thread-identification-guide | -20 (1 ¼) | 11½ | 42.2 | 1.66 | 40.1 | 1.58 | null | null | NPT | 11½ | https://referencesource.org/plumbing-fitting-thread-standards/npt-1-3/ | [
"major_diameter_mm",
"nominal_size",
"threads_per_inch"
] |
[
"thread_standard"
] | null | null | npt-1-5 | 48.3 | null | 1 ½ | https://trimantec.com/blogs/t/thread-identification-guide | -24 (1 ½) | 11½ | 48.3 | 1.90 | 46.2 | 1.82 | null | null | NPT | 11½ | https://referencesource.org/plumbing-fitting-thread-standards/npt-1-5/ | [
"major_diameter_mm",
"nominal_size",
"threads_per_inch"
] |
[
"thread_standard"
] | null | null | npt-5-8 | 22.9 | null | 5/8 | https://trimantec.com/blogs/t/thread-identification-guide | -10 (5/8) | 14 | 22.9 | 0.90 | 21.1 | 0.83 | null | null | NPT | 14 | https://referencesource.org/plumbing-fitting-thread-standards/npt-5-8/ | [
"major_diameter_mm",
"nominal_size",
"threads_per_inch"
] |
Plumbing fitting and pipe thread standards
Canonical, always-current version: https://referencesource.org/plumbing-fitting-thread-standards/ Machine-readable: https://referencesource.org/plumbing-fitting-thread-standards/data.json — this mirror is a point-in-time copy.
- Last verified: 2026-08-12
- Stale after: 2028-08-11 (past this date, prefer the canonical copy — it re-verifies on a cadence this snapshot does not)
- Records: 97
Dimensional specifications for NPT and BSP pipe thread sizes used in plumbing, hydraulic, and gas fittings worldwide. For each nominal pipe size within each standard, gives threads per inch, pitch, major diameter, and minor diameter — the numbers needed to identify an unknown thread or confirm whether two fittings will mate. Combines American (ASME B1.20.1) and British/ISO (ISO 228, ISO 7) standards in one table so the critical differences are visible side by side.
Provenance — what every record carries
Every record carries source (the URL the value was read from) and
source_quote (a verbatim quote from that page stating it). A value you
cannot check against its page is indistinguishable from an invented one;
these can all be checked. Each record is also individually addressable on
the canonical site at its url.
Licence position
factual compilation of thread dimensions from public reference sources; facts cited with attributed quotes, no standard document reproduced
Facts are not copyrightable; what this dataset takes from each source is a fact plus a short attributed quote linking back to the page that states it.
Sources
- https://www.machiningdoctor.com/charts/bsp/
- https://en.wikipedia.org/wiki/National_pipe_thread
- https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained
- https://amesweb.info/Screws/BSP-Thread-Chart.aspx
- https://en.wikipedia.org/wiki/British_Standard_Pipe
- https://www.geminivalve.com/bsp-thread-vs-npt-fitting/
- https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings
- https://trimantec.com/blogs/t/thread-identification-guide
Fields
See any record in data/records.jsonl — field names are self-describing,
and the canonical page for each record renders them with labels:
https://referencesource.org/plumbing-fitting-thread-standards/
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