# 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?

- Category: Tri-clamp & pipe › Pipe, tube & threads
- Kind: 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
- Page: https://xemstudio.com/objects/an-jic-37-degree-flare-fittings/ · JSON: https://xemstudio.com/api/geometry?object=an-jic-37-degree-flare-fittings · Plain text: https://xemstudio.com/objects/an-jic-37-degree-flare-fittings/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files CC BY 4.0 or their publisher's license
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

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

## 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.

## Sizes

| 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

- Wikipedia: [AN thread (sizes, 37° flare)](https://en.wikipedia.org/wiki/AN_thread) — web — Publisher's page; dimensions are facts
- Chase Bays: [AN plumbing info and thread chart](https://www.chasebays.com/pages/an-plumbing-info-and-thread-chart) — web — Publisher's page; dimensions are facts
- Hardin Marine: [AN fitting size guide](https://www.hardin-marine.com/t-an-fittings-guide.aspx) — 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)](https://s29.q4cdn.com/619069826/files/doc_downloads/2025/Jan/SAE37-FLARE-2025.pdf) — web — Publisher's page; dimensions are facts

## Questions

**What thread is -6 AN?**

9/16-18 UNF (14.29 mm major), for 3/8 in tube; hose ID about 5/16 in.

**Are AN and JIC the same?**

Both use a 37° flare and the same threads; JIC is the SAE J514 hydraulic version of AN. 45° SAE flares are different and do not interchange.

## Fits with

- [NPT male thread envelopes 1/8 to 1 in (ASME B1.20.1)](https://xemstudio.com/objects/npt-thread-envelopes/)
- [BSP (G) male thread envelopes 1/8 to 1 in (ISO 228-1)](https://xemstudio.com/objects/bsp-thread-envelopes/)
- [Push-fit fitting envelopes: 4 / 6 / 8 mm tube, G1/8 and G1/4 thread stubs](https://xemstudio.com/objects/push-fit-fittings/)
- [Hose barbs for 2, 3, 4, 6 and 8 mm ID tube](https://xemstudio.com/objects/hose-barbs/)