FittingKey

Provenance

Where every number came from

23 published documents, 3 of them standards read directly. No row in the database rests on a single source. Where two publishers disagreed, the disagreement is printed rather than smoothed over; where a figure could only be found once, it is not published at all and is listed below instead.

23
sources
5
disagreements
13
stated gaps

The rules this database is built to

  1. No row is published from a single source. Every one of the 110 sizes carries at least two independent publishers, and "independent" means different publishers: two pages of one catalogue are one source.
  2. Nothing is interpolated. A figure only one publisher carries is not here. A missing value renders as a stated gap, never as a guess.
  3. A disagreement is reported, not resolved. Both figures are printed with the reason they differ, or neither is printed.
  4. Pressure is the strictest field. It appears only where two independent publishers give the same figure under conditions they both state, and it is never shown without those conditions. Five of the 10 standards carry no pressure at all.
  5. Test fixtures are never derived from the database. The expectations in the test suite were re-read off the source documents and typed in by hand, so a bad transcription fails a test instead of agreeing with one.

Dimensions reflect ANSI/ASME B1.20.1-1983 Table 1, ISO 228-1:2000 Table 1, ISO 7-1:1994 Table 1, and manufacturer identification charts and catalogues citing SAE J512, SAE J514, SAE J1453, SAE J1926-1, ISO 8434-1, ISO 11926-1, DIN 2353 and JIS.

The register

Documents read

Manufacturer catalogues and charts

Distributor identification guides

Reference tables

Per standard

What each source supplied

JIC 37 degree flare (SAE J514 / ISO 8434-2)

Defined by SAE J514 and ISO 8434-2.

Sources behind each column of the JIC 37 degree flare table.
ColumnSourcesWhat they gave
Dash and trade sizetompkins, mcgill-id, chs-orfs, gageref-jicFour publishers give the same dash-to-tube-size map. Three of them carry the -14 row; one omits it.
Thread designation and pitchtompkins, mcgill-id, chs-orfs, gageref-jicAll four give the same thread for every dash size, including the 12 TPI constant-pitch series from -12 upward.
Basic major diametertompkins, mcgill-idThe thread designation fixes the basic major diameter: a 3/4-16 UNF thread has a basic major diameter of 0.750 in, which is 19.05 mm at 1 in = 25.4 mm exactly. The inch and millimetre columns are that one figure in two units.
Measured male thread diametergates-idchart, apex-threadid, mcgill-idThree identification charts. Their figures sit within 0.25 mm of one another, and the span of all three is what the size page publishes.
Working pressuretompkins, brennan-pressureTwo manufacturer catalogues, both stating a steel fitting at a 4 to 1 design factor against minimum burst per SAE J514. They agree on all thirteen sizes to the psi.

SAE straight thread O-ring boss, ORB (SAE J1926-1 / ISO 11926-1)

Defined by SAE J1926-1 and ISO 11926-1.

Sources behind each column of the SAE O-ring boss table.
ColumnSourcesWhat they gave
Dash and trade sizetompkins, mcgill-id, chs-orfs, gates-idchartFour publishers, same dash-to-port-size map, and all four give the ORB thread as identical to the JIC thread of the same dash.
Basic major diametertompkins, mcgill-idThe thread designation fixes the basic major diameter: a 3/4-16 UNF thread has a basic major diameter of 0.750 in, which is 19.05 mm at 1 in = 25.4 mm exactly. The inch and millimetre columns are that one figure in two units.
Measured male thread diametergates-idchart, mcgill-idTwo identification charts, within 0.25 mm at every size.
O-ring sizeglobaloring, gates-idchartThe AS568 900-series dash number comes from the O-ring maker's table, indexed by nominal port size. It was cross-checked against the measured O-ring inside diameters printed on the coupling chart: all thirteen agree to within 0.1 mm.
Working pressuretompkins, brennan-pressureTwo catalogues, steel, 4 to 1 against minimum burst per SAE J514, each giving a separate figure for a straight stud and for an adjustable stud. Both pairs match on all thirteen sizes.

O-ring face seal, ORFS (SAE J1453 / ISO 8434-3)

Defined by SAE J1453 and ISO 8434-3.

Sources behind each column of the ORFS (O-ring face seal) table.
ColumnSourcesWhat they gave
Dash and trade sizetompkins, mcgill-id, gageref-orfs, chs-orfsFour publishers agree the series runs -04 to -24. One adds a -14 and a -32 that no other source carries; both are recorded as gaps rather than published.
Basic major diametertompkins, mcgill-idThe thread designation fixes the basic major diameter: a 3/4-16 UNF thread has a basic major diameter of 0.750 in, which is 19.05 mm at 1 in = 25.4 mm exactly. The inch and millimetre columns are that one figure in two units.
Measured male thread diameterapex-threadid, mcgill-idTwo identification charts. A third prints 22.0 mm at -08, which fits neither the thread nor its own female figure, and is recorded as a disagreement instead of being averaged in.
O-ring sizeglobaloring, chs-orfsThe AS568 zero-series dash numbers are identical in both: 011, 012, 014, 016, 018, 021, 025 and 029.
Working pressuretompkins, brennan-pressureTwo catalogues, steel, 4 to 1 against minimum burst per SAE J1453, straight and adjustable studs given separately. Both pairs match on all eight sizes.

SAE 45 degree flare (SAE J512 / SAE J533)

Defined by SAE J512.

Sources behind each column of the SAE 45 degree flare table.
ColumnSourcesWhat they gave
Dash and trade sizeryco-sae, mcgill-id, gates-idchartThree publishers agree on the eight sizes carried here. One extends the series to -14 and -16; those two are recorded as gaps.
Basic major diameterryco-sae, mcgill-idThe thread designation fixes the basic major diameter: a 3/4-16 UNF thread has a basic major diameter of 0.750 in, which is 19.05 mm at 1 in = 25.4 mm exactly. The inch and millimetre columns are that one figure in two units.
Measured male thread diametergates-idchart, mcgill-idTwo identification charts, for the six sizes both carry.
Working pressureryco-sae, mcgill-idNeither publisher gives a working pressure for this connection, so none is published. Ratings are per part, from the maker's catalogue.

American National Pipe Taper, NPT (ASME B1.20.1) and NPTF dryseal (ASME B1.20.3)

Defined by ASME B1.20.1 (NPT) and ASME B1.20.3 (NPTF dryseal).

Sources behind each column of the NPT / NPTF table.
ColumnSourcesWhat they gave
Basic major diameterasme-b1201, amesweb-npt, machiningdoctor-nptThe basic major diameter D is the outside diameter of the pipe, read directly from ASME B1.20.1-1983 Table 1 and matched to four decimal places by two independent reproductions of that table.
Measured male thread diametergerrard-id, gates-idchart, mcgill-idThree charts measuring a tapered thread at three different planes. The span is wide on purpose - a 1 in 16 taper means the reading depends on where the caliper sits.
Working pressuretompkins, brennan-pressureTwo catalogues, steel, 4 to 1 against minimum burst per SAE J514. They agree from 1/2 upward and disagree by one whole pipe size at 1/4 and 3/8, where no figure is published.

British Standard Pipe Parallel, BSPP or G (ISO 228-1)

Defined by ISO 228-1 (and BS 2779).

Sources behind each column of the BSPP (G) table.
ColumnSourcesWhat they gave
Basic major diameteriso-228-1, amesweb-bspp, machiningdoctor-bspMajor, pitch and minor diameters read directly from ISO 228-1:2000 Table 1, and matched to three decimal places by two independent reproductions.
Measured male thread diametergerrard-id, adaptall-british, gates-idchart, apex-threadidFour identification charts. Three print identical figures at every size; the fourth rounds up by 0.1 mm. The span covers all four.
Working pressuregates-idchart, mcgill-idNeither identification source gives a working pressure for a BSPP connection, and none is published. It depends on the port form and the seal, not on the thread.

British Standard Pipe Taper, BSPT, R external and Rc internal (ISO 7-1)

Defined by ISO 7-1 (and BS 21).

Sources behind each column of the BSPT (R) table.
ColumnSourcesWhat they gave
Basic major diameteriso-7-1, machiningdoctor-bspRead directly from ISO 7-1:1994 Table 1, where the major diameter is defined AT THE GAUGE PLANE, and matched by an independent reproduction. ISO 7-1 lists no 5/8 and no 7/8 size.
Measured male thread diametergerrard-id, adaptall-british, gates-idchartThree charts measuring at three planes on a taper, differing by up to 0.8 mm. Every size page publishes the whole span and says why it is wide.

Metric 24 degree cone, DIN 2353 / ISO 8434-1, light (L) and heavy (S) series

Defined by ISO 8434-1 and DIN 2353.

Sources behind each column of the Metric DIN 24 degree table.
ColumnSourcesWhat they gave
Dash and trade sizegates-idchart, adaptall-24, mcgill-id, apex-threadidFour publishers give the same thread-to-tube map for both series, including the eight threads that carry a different tube size in each series.
Basic major diametergates-idchart, mcgill-idThe basic major diameter of an ISO metric thread is the number in its designation: M18 x 1.5 measures 18 mm across the crests. Both charts print exactly that.
Working pressuretubes-int, adaptall-24One publisher gives the ISO 8434-1 cutting-ring figure together with the spread across producers and states the conditions in full - carbon or stainless steel, static, safety factor 4. The other gives a single figure per size band. Where they differ the page prints both.

JIS 30 degree flare on a BSPP thread (JIS B 0202 thread form)

Defined by JIS B 0202 thread form (identical to ISO 228-1) with a 30 degree seat.

Sources behind each column of the JIS 30 degree flare (BSPP) table.
ColumnSourcesWhat they gave
Dash and trade sizegates-idchart, mcgill-idTwo identification guides, agreeing on the nine sizes published here. One also carries a G 1/8, recorded as a gap.
Basic major diameteriso-228-1, gates-idchartBoth guides state the thread is BSPP, so the basic diameters are ISO 228-1 Table 1 values read directly from the standard.
Measured male thread diametergates-idchart, mcgill-idTwo identification guides, within 0.8 mm at every size.

Komatsu style 30 degree flare on a metric thread

Defined by ISO 261 metric thread with a 30 degree seat, per manufacturer catalogues.

Sources behind each column of the Komatsu 30 degree flare (metric) table.
ColumnSourcesWhat they gave
Dash and trade sizegates-idchart, mcgill-idTwo identification guides agree on seven threads. One carries an M14 x 1.5 the other does not, and it is recorded as a gap.
Basic major diametergates-idchart, mcgill-idThe basic major diameter is the M number, and both charts print exactly that.
Tube outside diametergates-idchart, mcgill-idThe two disagree on the tube diameter for M18 x 1.5 and M22 x 1.5, so no tube size is published for those two threads.

Not resolved

Where two publishers disagree

ORFS -08 male thread diameter

  • 22.0 mm (gates-idchart)
  • 20.6 mm (apex-threadid)
  • 20.8 mm (mcgill-id)

22.0 mm cannot be a 13/16 in thread, whose basic major diameter is 20.64 mm, and the same chart gives a female inside diameter of 19.1 mm, which only fits the smaller figure. The outlier is treated as a misprint and excluded from the published span, and it is recorded here so nobody has to work that out twice.

Printed on: ORFS (O-ring face seal)

BSPT male thread diameter, every size

  • 12.8 mm at R 1/4, at the first full thread from the end (gerrard-id)
  • 13.1 mm at R 1/4, near the gauge plane (adaptall-british)
  • 13.6 mm at R 1/4, at the largest point (gates-idchart)

All three are correct measurements of the same fitting. A 1 in 16 taper loses 1.59 mm of diameter over 25.4 mm of length, so where the caliper sits decides the reading. The size page publishes the whole span, and the basic column carries the gauge-plane diameter from ISO 7-1 Table 1, which is the figure a thread gauge checks.

Printed on: BSPT (R)

NPTF working pressure at 1/4 and 3/8 nominal pipe size

  • 5,000 psi at 1/4 and 4,000 psi at 3/8 (tompkins)
  • 4,000 psi at 1/4 and 3,000 psi at 3/8 (brennan-pressure)

Both tables state the same basis - steel, 4 to 1 against minimum burst - and agree exactly from 1/2 upward, so the gap is a one-size offset in one of them rather than a difference of design intent. No working pressure is published at 1/4 or 3/8. Take it from the catalogue of the fitting you are installing.

Printed on: NPT / NPTF

DIN 2353 heavy series, 30 mm tube, working pressure

  • 400 bar (adaptall-24)
  • 250 bar as the ISO 8434-1 cutting-ring figure, 250 to 315 bar across producers (tubes-int)

The 400 bar figure sits outside the producer range the other source publishes for the same size band, which is the only place in the metric table where that happens. Both figures are printed on the size page. Assume the lower one unless the fitting's own catalogue says otherwise.

Printed on: Metric DIN 24 degree

Komatsu tube diameter at M18 x 1.5 and M22 x 1.5

  • 9.5 mm and 13.0 mm (gates-idchart)
  • 9 mm and 12 mm (mcgill-id)

One chart appears to be giving the inch tube sizes these threads serve converted to millimetres (3/8 in and 1/2 in), the other the nearest metric tube. No tube size is published for those two threads. The thread and the seat are agreed and are what identifies the fitting.

Printed on: Komatsu 30 degree flare (metric)

Absent on purpose

What this database does not have

A reference site that hides its gaps is claiming a completeness it does not have. Each entry below is a figure that exists somewhere in print but could only be corroborated once, so it is not published here.

ORFS -14 and -32

One distributor's adapter sizing chart lists an ORFS -14 at 1 5/16-12 and an ORFS -32 at 2 1/2-12. No other publisher carries either size: four sources stop the ORFS series at -24 (2-12), and both O-ring registers stop there too. Neither size is published rather than resting on one source.

Sources consulted: chs-orfs, tompkins, gageref-orfs, globaloring.

ORFS -08 male thread diameter

One identification chart prints 22.0 mm for the -08 male thread. That does not fit a 13/16 in thread, whose basic major diameter is 20.64 mm, and it does not fit the same chart's own female figure of 19.1 mm either. Two other publishers give 20.6 mm and 20.8 mm. The outlier is recorded here and left out of the published span on the size page.

Sources consulted: gates-idchart, apex-threadid, mcgill-id.

SAE 45 degree flare, -14 and -16

One identification guide extends the SAE 45 series to -14 (1 1/4-12) and -16 (1 3/8-12). The other two sources stop at -12. Those two sizes are not published here.

Sources consulted: mcgill-id, ryco-sae, gates-idchart.

SAE 45 degree flare working pressure

No two independent publishers in this register give a working pressure for the SAE 45 degree flare. It is a low and medium pressure joint used on refrigeration, fuel and brake lines rather than a hydraulic power connection, and makers rate it per part rather than per size. No figure is published.

Sources consulted: ryco-sae, mcgill-id.

NPT and NPTF working pressure at 1/4 and 3/8

The two catalogues that publish an SAE J514 pipe-thread working pressure disagree at these two sizes by one whole pipe size: 5,000 against 4,000 psi at 1/4, and 4,000 against 3,000 psi at 3/8, both at the same 4 to 1 design factor. From 1/2 upward they agree exactly. No figure is published for 1/4 or 3/8.

Sources consulted: tompkins, brennan-pressure.

NPT 1/16 working pressure

Only one of the two pipe-thread pressure tables carries a 1/16 row. The dimension is published from ASME B1.20.1 Table 1; the pressure is not.

Sources consulted: tompkins, asme-b1201.

BSPT 5/8 and 7/8 (R 5/8, R 7/8)

ISO 7-1:1994 Table 1 lists no 5/8 and no 7/8 size. Some identification charts print a 5/8 row as trade practice. G 5/8 and G 7/8 are standard BSPP sizes in ISO 228-1 and are included here; R 5/8 and R 7/8 are not.

Sources consulted: iso-7-1, iso-228-1, gates-idchart.

BSPT measured male thread diameter

Three publishers disagree by up to 0.8 mm at every size, because they measure at different planes on a tapered thread: one at the first full thread at the entering end, one near the gauge plane, one at the largest point by the hex. None is wrong. Every BSPT size page publishes the whole span and the gauge-plane figure from ISO 7-1 Table 1, rather than one measured number that would be right at a single plane only.

Sources consulted: gerrard-id, adaptall-british, gates-idchart.

Komatsu M14 x 1.5, and Komatsu tube sizes

One chart carries a Komatsu M14 x 1.5; the other starts the series at M18 x 1.5, so M14 is not published. The two also give different tube diameters for M18 x 1.5 and M22 x 1.5 (9 against 9.5 mm, 12 against 13 mm), so no tube size is published for those two threads. The threads themselves and the 30 degree seat are agreed.

Sources consulted: gates-idchart, mcgill-id.

JIS 30 degree G 1/8

One guide carries a JIS 30 degree flare at G 1/8. The other identification chart starts the series at G 1/4. The size is not published.

Sources consulted: mcgill-id, gates-idchart.

24 degree cone mouth and bore diameters

No two publishers in this register tabulate the cone mouth and bore dimensions that differ between a light-series and a heavy-series fitting sharing one thread. That they differ is corroborated four times over and is stated on every metric size page; the millimetre values are not tabulated.

Sources consulted: gates-idchart, adaptall-24, mcgill-id, apex-threadid.

NPTF taper-angle tolerance and gauging

A tighter taper tolerance and a four-gauge inspection requirement for NPTF appear in one reference only. ASME B1.20.3 itself was not read, so neither figure is published here.

Sources consulted: machiningdoctor-npt.

Working pressure for BSPP, BSPT, JIS and Komatsu connections

No two independent publishers in this register give a working pressure for any of these four. Ratings vary by manufacturer, body material, port form and seal, and a number carried here without its conditions would be worse than no number. Read the figure from the catalogue of the fitting you are installing.

Sources consulted: gates-idchart, mcgill-id.

Corrections

If a figure here disagrees with a document you have, that is worth knowing about. Send the publisher, the edition and the page to socialreminderinfo@gmail.com and it will be checked against the register.

FittingKey is an independent reference. It is not affiliated with, endorsed by or connected to SAE International, ISO, ASME, DIN, JIS, or any fitting manufacturer. Standard names are used only to refer to the published standards themselves. This site is a reference aid for identification and ordering, not a substitute for the manufacturer specification.