SAE 45° flare fittings: tube OD, thread (5/16-24 to 1-1/4-12), nut hex and length, 1/8 to 7/8 in — dimension sheet Source: Xem Studio, https://xemstudio.com/objects/sae-45-degree-flare-nuts-and-threads/ (sheet CC BY 4.0) Basis: Parker Hannifin catalogue 3501E (41FL, 41FS) and SC Fastening nut pages, thread list checked on McMaster-Carr; SAE J512 / J513 not read; McMaster-Carr linked for CAD Catalog version: 2026-10-20 Sizes: see table below - SAE 45° flare (the tube end is flared to 45°, the nut pulls it against a male cone). The size name is the TUBE OD; the dash number is the tube OD in sixteenths of an inch (-4 = 1/4 in tube). Threads are straight UNF: 1/8 in tube 5/16-24, 3/16 in 3/8-24, 1/4 in 7/16-20, 5/16 in 1/2-20, 3/8 in 5/8-18, 1/2 in 3/4-16, 5/8 in 7/8-14, 3/4 in 1-1/16-14, 7/8 in 1-1/4-12. These match Parker's catalogue for every size and the thread list on McMaster-Carr's 45° flared fittings page. The governing standards are SAE J512 and J513; their text is paywalled and was not read. - Do not mix with 37° (AN / JIC) or with compression nuts: 1/4 in flare is 7/16-20 (this page), 1/4 in compression is 7/16-24, and the 37° AN -4 is also 7/16-20 with a different seat. See 'an-jic-37-degree-flare-fittings' for 37°. A 7/16-20 nut cross-threads on a 7/16-24 fitting, and 45° and 37° seats leak against each other. - Numbers: Parker catalogue 3501E (long nut 41FL and short nut 41FS / 41FX, pages H4-H10, read through a SlideShare copy): hex c, length l and a dimension 'd' that Parker's page labels without a definition (it is the tube OD plus about 0.007 in); the 41FX 'shorter' nut (3/8 l 0.91, 1/2 l 1.00, 5/8 l 1.06, 3/4 l 1.17) is not tabulated. SC Fastening's catalogue pages give an independent set for a short rod nut (A = length, hex): its A and hex equal Parker's short nut for 1/8, 3/16, 1/4, 5/16 in (hex 0.37 vs 3/8 and so on is rounding); its long forged nut differs from Parker's long nut (1/4 in hex 0.62 vs 9/16, 3/8 in A 1.06 vs l 1.31), so both are shown rather than merged. Dash sizes follow Parker's part numbers (41FS-2 to 41FS-14). - Files (17): hex envelopes of Parker's short nut (9 sizes) and long nut (8 sizes): hex across flats c, length l, a through hole at the tube OD. No internal thread, no 45° seat, no tube relief, because none is published; the thread size is in the file name only. The dimension the nut screws onto (male thread, 45° cone, flare diameter) is not published in a readable table, so no fitting body is drawn. - Left out: flare diameters and the 45° flare envelope (SAE J533 / J512 values were not readable here; the 37° page lists J533 ranges), male and female connector bodies, elbows and tees (A, B, C columns of the catalogues could not be matched to the drawings), hose sizes, working pressures, and the Parker 41FX shorter nut. McMaster-Carr's category (linked) offers per-part STEP / IGES. dash size tube OD, in (mm) nut thread, UNF (major, mm) Parker short nut 41FS: hex / length l, in Parker long nut 41FL: hex / length l, in Parker d, in SC Fastening short rod nut: A / hex, in SC Fastening long forged nut: A / hex, in -2 1/8 (3.17) 5/16-24 (major 7.94) 3/8 / 0.50 3/8 / 0.75 0.133 0.50 / 0.37 — -3 3/16 (4.76) 3/8-24 (major 9.52) 7/16 / 0.62 7/16 / 0.81 0.195 0.62 / 0.43 — -4 1/4 (6.35) 7/16-20 (major 11.11) 9/16 / 0.75 9/16 / 0.94 0.257 0.75 / 0.56 0.94 / 0.62 -5 5/16 (7.94) 1/2-20 (major 12.70) 5/8 / 0.88 5/8 / 1.12 0.320 0.88 / 0.62 — -6 3/8 (9.52) 5/8-18 (major 15.88) 3/4 / 1.00 3/4 / 1.31 0.382 — 1.06 / 0.81 -8 1/2 (12.70) 3/4-16 (major 19.05) 7/8 / 1.12 7/8 / 1.62 0.507 — 1.19 / 0.94 -10 5/8 (15.88) 7/8-14 (major 22.22) 1-1/16 / 1.31 1-1/16 / 1.88 0.632 — 1.44 / 1.06 -12 3/4 (19.05) 1-1/16-14 (major 26.99) 1-1/4 / 1.50 1-1/4 / 2.19 0.757 — 1.75 / 1.31 -14 7/8 (22.22) 1-1/4-12 (major 31.75) 1-1/2 / 1.62 — 0.882 — — Files elsewhere (not hosted by Xem Studio; license as stated by the publisher): - Parker Hannifin (catalog 3501E, hosted on SlideShare): 45 degree flare fittings, pages H4-H10: 41FL long nut and 41FS / 41FX short nut: thread, hex c, d, length l — web — Publisher's page; dimensions are facts — https://www.slideshare.net/tedtall/flare-fitting - SC Fastening (JB-style catalogue): SAE 45 flare short rod nut: tube OD, thread, A, hex — web — Publisher's page; dimensions are facts — https://catalog.scfastening.com/compare/umbing-brass-fittings-sae-45-degree-flare-fittings/g-brass-fittings-sae-45-degree-flare-short-rod-nut - SC Fastening (JB-style catalogue): SAE 45 flare long forged nut: tube OD, thread, A, hex — web — Publisher's page; dimensions are facts — https://catalog.scfastening.com/compare/umbing-brass-fittings-sae-45-degree-flare-fittings/brass-fittings-sae-45-degree-flare-long-forged-nut - McMaster-Carr: 45-degree flared tube fittings (free STEP/IGES per part, for your own design use; no redistribution) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution [verify license at link] — https://www.mcmaster.com/products/45-degree-flared-tube-fittings Free files (CC BY 4.0, Xem Studio; STEP + STL, 17 parts): https://xemstudio.com/files/hardware/sae-45-degree-flare-nuts-and-threads/index.json API: https://xemstudio.com/api/geometry?object=sae-45-degree-flare-nuts-and-threads