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AN and JIC 37° flare fittings: dash sizes -3 to -20, thread, tube OD, hose ID, flare diameter

What thread, tube OD and hose size is an AN -6 or -8 fitting? · Standard part · basis: AN thread (Wikipedia), Chase Bays and Hardin Marine AN charts, Ham-Let SAE 37° flare catalogue (SAE J533 flare diameter, hexes); numbers only

Also called: an6 thread size, -8 an fitting, an fitting size chart, an to thread chart, jic 37 degree dimensions, -6 an 9/16-18, an vs npt, an hose id, an tube od, -10 an thread, jic vs sae 45, an wrench size

Exact dimensions. True size, with no printing tolerance added.

sizes: 9 in table

Notes

AN (and JIC) fittings seal on a 37° flare: the dash number is the tube OD in sixteenths of an inch (-6 = 6/16 = 3/8 in), not a thread. -6 is 9/16-18 UNF, -8 is 3/4-16, -10 is 7/8-14, and so on; the same threads as SAE O-ring ports. 37° AN/JIC and 45° SAE flares do not interchange.
Thread major diameters are the nominal diameter of the designation converted at 25.4 mm/in (a thread has a tolerance band). Hose ID is approximate: hose makers differ.
Flare diameter is the SAE J533 single-flare diameter range for the tube OD as printed by Ham-Let (UCT) in its 37° flare catalogue (inch values 0.26–0.28, 0.34–0.36, 0.46–0.49, 0.63–0.66, 1.17–1.20 converted to mm); wrench sizes are that maker's nut and connector hexes, and other makers differ. Charts for the other dashes did not print them.
Left out, no file: hex thickness, thread length and nose length are not printed in the charts we could read (Ham-Let prints thread, hex flats and overall length of its connectors, not the hex position), so no flare envelope is published.

AN and JIC 37° flare fittings: dash sizes -3 to -20, thread, tube… size chart

AN size	thread (UNF/UN)	tube OD	hose ID	flare angle	SAE J533 flare dia A (mm)	wrench hex (in, Ham-Let)
-3	3/8-24 (major 9.52 mm)	3/16 (4.76 mm)	1/8 (approx.)	37°	6.61–7.11	-
-4	7/16-20 (major 11.11 mm)	1/4 (6.35 mm)	3/16 (approx.)	37°	8.64–9.14	9/16 (nut and connector)
-5	1/2-20 (major 12.70 mm)	5/16 (7.94 mm)	1/4 (approx.)	37°	-	-
-6	9/16-18 (major 14.29 mm)	3/8 (9.52 mm)	5/16 (approx.)	37°	11.69–12.44	-
-8	3/4-16 (major 19.05 mm)	1/2 (12.70 mm)	7/16 (approx.)	37°	16.01–16.76	7/8 (nut and connector)
-10	7/8-14 (major 22.22 mm)	5/8 (15.88 mm)	1/2 (approx.)	37°	-	-
-12	1-1/16-12 (major 26.99 mm)	3/4 (19.05 mm)	5/8 (approx.)	37°	-	-
-16	1-5/16-12 (major 33.34 mm)	1 (25.40 mm)	7/8 (approx.)	37°	29.72–30.48	1-1/2 nut / 1-3/8 connector
-20	1-5/8-12 (major 41.27 mm)	1-1/4 (31.75 mm)	1-1/8 (approx.)	37°	-	-

Where the files are

Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.

Wikipedia	AN thread (sizes, 37° flare)	web	Publisher's page; dimensions are facts
Chase Bays	AN plumbing info and thread chart	web	Publisher's page; dimensions are facts
Hardin Marine	AN fitting size guide	web	Publisher's page; dimensions are facts
Ham-Let (UCT)	SAE 37° flare 3-piece tube assembly catalogue, Jan 2025 (J533 flare dia, nut and connector hexes)	web	Publisher's page; dimensions are facts

Xem scan

File coming

No downloadable true-size file yet: the published figures do not fix the whole shape, and Xem never guesses a number. A measured scan is planned; request it and it moves up.

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Plain text: sheet.txt · JSON: /api/geometry?object=an-jic-37-degree-flare-fittings

Schematic, not to scale.