pretty_name: Plumbing fitting and pipe thread standards
license: other
license_name: source-terms-cited
license_link: https://referencesource.org/plumbing-fitting-thread-standards/
language:
- en
tags:
- reference-data
- provenance
- referencesource-org
configs:
- config_name: default
data_files:
- split: train
path: data/records.jsonl
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;
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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://amesweb.info/Screws/BSP-Thread-Chart.aspx
- https://www.geminivalve.com/bsp-thread-vs-npt-fitting/
- https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings
- https://en.wikipedia.org/wiki/National_pipe_thread
- https://trimantec.com/blogs/t/thread-identification-guide
- https://www.machiningdoctor.com/charts/bsp/
- https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained
- https://en.wikipedia.org/wiki/British_Standard_Pipe
Fields
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and the canonical page for each record renders them with labels:
https://referencesource.org/plumbing-fitting-thread-standards/