ORFS O-ring face seal fittings (SAE J1453), dash -4 to -24: thread, tube OD, O-ring size, nut hex + lock-nut envelopes — dimension sheet Source: Xem Studio, https://xemstudio.com/objects/orfs-sae-j1453-o-ring-face-seal-ends/ (sheet CC BY 4.0) Basis: Brennan's ORFS catalog (nut, bulkhead lock nut and union dimensions), hoseandfittings' J1453 thread table and Parker's TFD O-ring sheet; eight lock-nut envelopes as files Catalog version: 2026-10-20 Overall (mm): length 69.7, width 60.3, height 10.4 - SAE J1453 O-ring face seal (ORFS, 'flat face O-ring', Seal-Lok in Parker's naming): a flat-faced male end carries an O-ring in a groove, and a swivel nut with a UN thread pulls it against the flat face of the mating end. The dash number is the tube OD in sixteenths of an inch, as for AN / JIC (-8 = 1/2 in), but the thread is different from the AN / JIC and SAE O-ring boss thread at most sizes: -4 is 9/16-18, -6 11/16-16, -8 13/16-16, -10 1-14, -12 1 3/16-12, -16 1 7/16-12, -20 1 11/16-12, -24 2-12. ORFS and 37° flare or O-ring boss ends do not interchange even where a thread size happens to coincide (9/16-18 is -4 ORFS and -6 AN). - Brennan's ORFS catalog (the source of the thread, nut hex, nut width and union hex): the nut (FS0318) lists thread A, hex B and width Q; the bulkhead lock nut (FS0306) lists thread A, hex B and width TT; the same-size straight union (FS2403, male-to-male) lists hex H. All are in inches as printed (mm are Xem's conversions at 25.4). Thread and hex sizes are the same across the sizes Brennan lists. hoseandfittings' 'flat face O-ring (FFS), SAE J1453' table gives the male thread OD and female thread ID per dash (its 1 in row prints the female ID as '1-3/4 (1.36)', which looks like a typo for 1-5/16; reproduced as printed). - O-rings: Parker Tube Fittings Division's TFD O-ring sheet lists the ORFS face-seal O-ring for each dash as AS568 2-011 (-4), 2-012 (-6), 2-014 (-8), 2-016 (-10), 2-018 (-12), 2-020 (-14), 2-021 (-16), 2-025 (-20), 2-029 (-24) and 2-135 (-32), ID and W in inches and mm as printed (W 0.07 in / 1.78 mm up to -24, 0.10 / 2.54 for the -32). Dash -14 and -32 are not in the Brennan catalog's tables read, so their threads and hexes are left out. - Files: eight bulkhead lock-nut envelopes (dash -4 to -24): a hex prism of the published across-flats and width with a plain bore at the thread's nominal major diameter. They are envelopes: chamfers and the real thread are not drawn. Only Brennan prints the nut hex, width and lock-nut figures, so these come from one maker's catalog. The male ORFS end (groove, flat face, tube stub) and the swivel nut's tube lip are not published as numbers in the sources read, so no end solid is drawn. - Related: AN / JIC 37° flare (an-jic-37-degree-flare-fittings), SAE 45° flare (sae-45-degree-flare-nuts-and-threads), O-ring boss ports (sae-j1926-iso-11926-o-ring-boss-ports). McMaster-Carr sells ORFS fittings with per-part STEP; no per-part link was read. dash tube OD (in) thread (UN) nut hex B (FS0318) nut width Q (in) lock nut hex B (FS0306) lock nut width TT (in) union hex H (FS2403, in) male thread OD / female ID (in, as printed) face-seal O-ring (Parker, AS568) -4 1/4 9/16-18 0.687 in (17.45 mm) 0.580 0.812 in (20.62 mm) 0.270 0.625 9/16 (0.56) / 17/32 (0.51) 2-011 (ID 0.30 / 7.7 in / mm, W 0.07 / 1.78) -6 3/8 11/16-16 0.812 in (20.62 mm) 0.670 1.000 in (25.40 mm) 0.310 0.750 11/16 (0.69) / 5/8 (0.63) 2-012 (ID 0.36 / 9.3 in / mm, W 0.07 / 1.78) -8 1/2 13/16-16 0.938 in (23.83 mm) 0.827 1.125 in (28.57 mm) 0.350 0.875 13/16 (0.82) / 3/4 (0.75) 2-014 (ID 0.49 / 12.4 in / mm, W 0.07 / 1.78) -10 5/8 1-14 1.125 in (28.57 mm) 0.925 1.312 in (33.32 mm) 0.410 1.062 1 (1.00) / 15/16 (0.93) 2-016 (ID 0.61 / 15.6 in / mm, W 0.07 / 1.78) -12 3/4 1 3/16-12 1.375 in (34.92 mm) 1.024 1.500 in (38.10 mm) 0.410 1.250 1-3/16 (1.19) / 1-1/8 (1.11) 2-018 (ID 0.74 / 18.8 in / mm, W 0.07 / 1.78) -16 1 1 7/16-12 1.625 in (41.27 mm) 1.095 1.750 in (44.45 mm) 0.410 1.500 1-7/16 (1.44) / 1-3/4 [sic] (1.36) 2-021 (ID 0.93 / 23.5 in / mm, W 0.07 / 1.78) -20 1 1/4 1 11/16-12 1.875 in (47.62 mm) 1.095 2.000 in (50.80 mm) 0.410 1.750 1-11/16 (1.69) / 1-5/8 (1.61) 2-025 (ID 1.18 / 29.9 in / mm, W 0.07 / 1.78) -24 1 1/2 2-12 2.250 in (57.15 mm) 1.095 2.375 in (60.32 mm) 0.410 2.125 2 (2.00) / 1-15/16 (1.92) 2-029 (ID 1.49 / 37.8 in / mm, W 0.07 / 1.78) Files elsewhere (not hosted by Xem Studio; license as stated by the publisher): - Brennan Industries: ORFS catalog: nut FS0318 (thread, hex, width), bulkhead lock nut FS0306 (thread, hex, width), straight FS2403 (hex) — web — Maker catalog; numbers only — https://irp.cdn-website.com/8b2b97ee/files/uploaded/Brennan+ORFS+Catalog.pdf - hoseandfittings.com: Flat Face O-Ring (FFS), SAE J1453: dash size, nominal thread, male thread OD, female thread ID — web — Distributor page; numbers only — https://hoseandfittings.com/?p=21040 - Parker Tube Fittings Division (hosted by Wilson Company): O-rings and seals: ORFS, SAE boss, ISO 6149, SAE 4-bolt flange O-ring sizes (ID, W) — web — Maker catalog pages; numbers only — https://wilson-company.com/images/document/TFD/O-Rings___Seals.pdf Free files (CC BY 4.0, Xem Studio; STEP + STL, 8 parts): https://xemstudio.com/files/hardware/orfs-sae-j1453-o-ring-face-seal-ends/index.json API: https://xemstudio.com/api/geometry?object=orfs-sae-j1453-o-ring-face-seal-ends