JIC 37° Flare Tube Fittings: Stainless Steel & Alloy (SAE J514)
A JIC 37° flare fitting is a tube connection that makes a metal-to-metal seal: a swivel nut clamps the 37° flared tube end against a matching 37° male cone, and the whole thing is standardized as SAE J514. Crestflo builds this end connection on stainless-steel and high-alloy instrumentation fittings, sized dimensionally to SAE J514 and ISO 8434-2. Coverage runs up to 2" (50 mm) OD, up to 15,000 PSI, and up to 350°C. Standard items ship from stock; specials are made to order, with 6-8 week delivery. These fittings are also built to meet PED requirements. On this page, "JIC 37° flare" refers specifically to the SAE J514 37° metal-to-metal flare interface used on stainless and alloy instrumentation and fluid-system fittings. It doesn't mean the SAE 45° flare found in automotive or refrigeration work, and it isn't a compression or ferrule connection either. Request a quote or request a free sample to specify yours.
Also Known As: JIC 37, SAE J514, JIC Flare & 37° Flare Designations
JIC fittings go by a lot of names, depending on who's buying and who's specifying. Call it a JIC fitting, JIC 37, JIC 37°, a JIC 37 degree flare, a 37 degree flare fitting, or just a JIC flare, and you're talking about the same interface. It shows up as JIC male, JIC female swivel, and JIC swivel configurations too. On the standards side, SAE J514 covers 37° flare tube fittings, while SAE J516 handles the companion hose-fitting spec. ISO 8434-2 is the ISO equivalent for 37° "SAE flare" fittings, and MIL-DTL-18866 covers the military version. The name JIC comes from Joint Industry Council, the group that first developed the 37° flare standard; SAE maintains it now. Stainless steel JIC fittings, JIC 37 flare fitting dimensions, JIC dash sizes, JIC thread sizes: however you flip the phrase or drill into the spec, it all traces back to the same SAE J514 seat.
What Is a JIC 37° Flare Fitting and How the 37° Metal-to-Metal Seal Works
A JIC 37° flare fitting makes its seal when the 37° cone face of a male nose meets a 37° flared tube end, or flare sleeve, and a swivel nut draws the two together until metal touches metal. No O-ring sits in that joint, no soft seat either. The flare face does the sealing work itself, which is exactly why the interface shrugs off high temperatures with no elastomer around to break down. That 37° half-angle comes from an industry standard, SAE J514, and it strikes a balance: a durable seal that can be remade across countless assemblies, without turning the flaring process into a chore. It's become the go-to choice for both hydraulic and instrument lines. JIC, being a standardized and non-proprietary interface, means one thing above all: any SAE J514-compliant JIC fitting will mate with another built to the same standard, no matter who made it.
JIC 37° Flare Size & Thread Chart: Dash -2 to -32 (SAE J514 Threads)
JIC fitting sizes come down to three things: dash size, tube OD, and a straight (parallel) UN/UNF thread. The chart below lists the standard SAE J514 dash sizes together with their nominal tube OD and thread series, including the UN/UNF thread pitch. These figures follow SAE J514, though they're adjustable to suit specific requirements. Sizes are offered in both imperial and metric tube dimensions.
| Dash | Tube OD (in) | Approx. mm | SAE J514 thread (UNF) |
|---|---|---|---|
| -2 | 1/8 | 3 | 5/16-24 |
| -3 | 3/16 | 5 | 3/8-24 |
| -4 | 1/4 | 6 | 7/16-20 |
| -5 | 5/16 | 8 | 1/2-20 |
| -6 | 3/8 | 10 | 9/16-18 |
| -8 | 1/2 | 12 | 3/4-16 |
| -10 | 5/8 | 16 | 7/8-14 |
| -12 | 3/4 | 20 | 1-1/16-12 |
| -14 | 7/8 | 22 | 1-3/16-12 |
| -16 | 1 | 25 | 1-5/16-12 |
| -20 | 1-1/4 | 32 | 1-5/8-12 |
| -24 | 1-1/2 | 38 | 1-7/8-12 |
| -32 | 2 | 50 | 2-1/2-12 |
The Crestflo 37° flare line handles up to 2" (50 mm) OD. If you're not sure whether an unknown thread is NPT or BSP, the thread identification guide will help you sort it out.
JIC 37° Flare Fitting Materials: 316/316L, 904L, Duplex, Inconel & Titanium
JIC 37° fittings come in the full stainless and high-alloy range. That's the detail separating instrumentation-grade JIC from the generic hydraulic-grade parts you'll find elsewhere. Standard stainless grades run 304/304L, 316/316L, and 904L. Corrosion-resistant and super-austenitic options include Duplex 2205, Super Duplex 2507, 254 SMO, AL-6XN, and Alloy 20. Nickel alloys span Inconel 600/601/625/718/825, Incoloy 800/800H/825, Monel 400/K500, Hastelloy C-276/C-22/B-2/B-3/X, and Nickel 200/201. Titanium Grade 2 rounds out the lineup. Sour service calls for alloys compliant with NACE MR0175 / ISO 15156-. Brass isn't part of the US line. Stainless and alloy only.
| Family | Representative grades | Grade page | Typical driver |
|---|---|---|---|
| Stainless | 316/316L, 904L | 316/316L · 904L | General corrosion, chloride resistance |
| Duplex / super-austenitic | Duplex 2205, Super Duplex 2507, 254 SMO, Alloy 20 | Duplex 2205 | Chloride SCC, strength |
| Nickel | Inconel 625, Inconel 825, Monel 400, Hastelloy C-276 | Inconel 625 | Sour/high-temp, aggressive media |
| Titanium | Titanium Grade 2 | Titanium Gr 2 | Seawater, weight-critical service |
You'll find grade education on the pages above. Crestflo, for its part, sells these grades as instrumentation fittings rather than mill forms. Sour-service selection points to NACE MR0175 and ISO 15156.
JIC 37° Pressure & Temperature Ratings and How It Seals
Crestflo 37° flare fittings carry a rating of up to 15,000 PSI working pressure and up to 350°C. The all-metal flare seal is what gives it that temperature capability, something an elastomer-sealed joint just can't match. Working pressure derates with tube size, wall thickness, temperature, and material. Ratings follow the applicable standard but can be customized to your requirement, so confirm the certified rating for your dash size and alloy on the RFQ. Need JIC service at or above 15,000 PSI? See 15,000 PSI high-pressure fittings. Assembly involves a controlled swivel-nut make-up onto the 37° seat. Stainless-on-stainless threads can gall during that process, though, so fittings are also available with silver anti-galling plating for stainless thread make-up. Material finish, electropolish, and passivation are options too, and O2-cleaning is available on request. If you're chasing a leak or need re-make guidance, see fitting-leak troubleshooting.
JIC 37° Fitting Types & Adapters: Male, Female Swivel, Union, Elbow & JIC-to-NPT
The JIC 37° line runs the complete configuration set: male connector, female swivel, union, bulkhead union, 45° and 90° elbows, run and branch tees, cross, cap, and plug. Adapters tie JIC 37° into other port types: JIC-to-NPT, JIC-to-BSP, JIC-to-metric, and JIC-to-tube (flare-to-compression), since the 37° flare line's compatible with Crestflo compression fittings. JIC-to-SAE-ORB adapters, for their part, connect to straight-thread O-ring boss ports, and the SAE O-ring boss (ORB) fittings page handles that detail on its own. Pipe-thread ends get separate coverage on the NPT-end tube fittings page. The standalone 37° JIC flare-fitting family carries the dedicated flare catalog line, while metric ports route to metric tube fittings.
JIC 37° vs SAE 45° vs AN 37° Flare: What Is (and Isn't) Interchangeable
JIC 37 or 45? People ask that constantly. It's 37°. The table below lines up JIC 37° against the flare interfaces it sits next to.
| Interface | Seat angle | Standard | Thread | Mates with JIC 37°? |
|---|---|---|---|---|
| JIC 37° flare | 37° | SAE J514 | Straight UN/UNF | Yes, by SAE J514 |
| SAE 45° flare | 45° | SAE J512 | Straight UN/UNF | No, different seat angle |
| AN 37° flare | 37° | AND/MS (aerospace) | Straight, aerospace class | Same seat, different thread class & material regime |
| JIS 30° flare | 30° | JIS B8363 | Metric/BSP | No, different seat angle |
A 37° flare and a 45° flare have nothing in common besides the word "flare." Don't mix them up. The seat angles won't match, and the joint will leak. AN and JIC fittings both use the 37° seat, yet they differ in thread class and material control. Treat them as separate systems entirely. For a closer look, check out JIC vs ORB and JIC vs DIN 2353.
JIC 37° Flare Fitting Applications: Hydraulics, Instrument & High-Vibration Lines
A 37° flare with a re-makeable metal seal holds up under vibration and hydraulic pressure. That's the reason JIC rules hydraulic power units and mobile equipment. Crestflo's instrumentation range extends the fitting further: high-vibration instrument lines, oil-and-gas process and sampling loops, and aerospace and defense fluid systems, anywhere a soft-seal joint won't do. One distinction matters here. "JIC hydraulic fittings" made from carbon or plated steel are commodity parts. Crestflo's JIC, by contrast, is stainless and alloy, built to instrumentation grade on that same interface. Explore hydraulics, oil and gas, and aerospace and defense applications.
Standards, Certifications & Traceability for JIC 37° Flare Fittings
Crestflo JIC 37° flare fittings meet SAE J514 and ISO 8434-2 for the 37° flare interface; SAE J516 serves as the companion hose standard, and MIL-DTL-18866 covers military JIC. The company holds ISO 9001 / 14001 / 45001 & PED certification. It also carries the standard approvals for compression tube fittings, including ASTM F1387 performance qualification, which covers the compression side and doesn't govern the flare seal itself, and it supplies NACE MR0175 / ISO 15156-compliant alloys for sour service. Traceability runs through EN 10204 MTC 3.1 as standard, with 3.2 available on request, and every part carries a marked heat/lot number. Testing spans hydraulic proof, burst and impulse, pneumatic, flexure fatigue, rotary flex, vibration, thermal cycling, pull-out, and vacuum, plus PMI. In-house NDT is standard practice. Destructive testing, though, takes place at ISO/IEC 17025-accredited labs. Certificates appear here in summary and in full at quality; see also ASTM F1387 and the NPT thread standard, ASME B1.20.1. The Crestflo Engineering Team reviewed this page.
Request a Quote, Sample or Cross-Reference for JIC 37° Flare Fittings
Every order is quoted, not carted. End users and EPC contractors can request a quote or a free sample; OEMs can ask about the private-label program. JIC is a standardized SAE J514 interface, so any compliant JIC fitting interchanges by the standard, for a Brennan, Parker Triple-Lok, or Eaton part-by-part equivalent, request your cross-reference from our engineering team via the master interchange and Brennan cross-reference pages. Triple-Lok is a trademark of Parker Hannifin Corporation; Crestflo is not affiliated with or endorsed by these companies. To receive the ordering-code guide for JIC series, size, end, material, thread, and finish options, ask our engineering team on the RFQ. Datasheets and CAD are available to customers on request.
Why Crestflo for JIC 37° Flare Fittings
Crestflo delivers instrumentation-grade JIC 37° flare fittings to SAE J514 dimensions, and its material range runs from 316L all the way through Inconel, duplex, and titanium. That's a depth of stock most hydraulic sellers simply don't carry. Standard items ship from ready stock; specials are made to order. Either way, expect a 6-8 week lead time, not the 20-plus weeks common among the majors. Small MOQ and private label are both available. Sizes come in imperial and metric, and every part ships with a heat number plus EN 10204 MTC 3.1. Origin is Indian, though US and European melt can be arranged on request, with full material traceability throughout. Crestflo is the instrumentation division of a four-decade-old export house recognized by the Government of India, one with a proven delivery record across the Middle East. For more, see why Crestflo, lead time, and testing and inspection.
JIC 37° Flare Fitting FAQ
What does JIC stand for on fittings?
JIC is short for Joint Industry Council. That group first developed the 37° flare standard, which SAE now maintains under the designation SAE J514.
Are all JIC fittings 37 degrees?
Yes. JIC fittings, by definition, use a 37° flare seat. A 45° flare is a different animal entirely: it falls under its own SAE standard, SAE J512, and it won't mate with JIC.
Why are JIC fittings 37 degrees?
The 37° cone sits at the center of SAE J514, the industry standard that made it the default choice for hydraulic and instrument lines. Why? It seals metal to metal, reliably, and you can remake that seal again and again across a wide range of assemblies. No soft seal needed.
Is JIC 37 or 45?
JIC uses a 37° angle. SAE's 45° flare, covered under SAE J512, is a different interface altogether and doesn't interchange with JIC. Mix a 37° flare with a 45° one, and leaks follow.
Do you offer stainless steel and alloy JIC fittings?
Yes, we carry 304/304L, 316/316L, 904L, Duplex 2205, Super Duplex 2507, 254 SMO, Alloy 20, Inconel, Incoloy, Monel, Hastelloy, and Nickel 200/201, along with Titanium Grade 2. Brass isn't part of the US line.
What sizes and threads do your JIC fittings come in?
Sizes run from dash -2 (1/8" tube) up to -32 (2" OD), all on straight UN/UNF threads per SAE J514. Take -8, for instance: that's 3/4-16. Check the size and thread chart above for the rest. The values come straight from SAE J514, though they can be adjusted to fit specific requirements.
What pressure and temperature can JIC 37° fittings take?
Up to 15,000 PSI working pressure and up to 350°C, though actual limits derate depending on size, material, and temperature. Ratings follow the applicable standard, and they can be customized to fit specific requirements.
Can I get a JIC-to-NPT or JIC-to-tube adapter?
Yes, JIC-to-NPT, JIC-to-SAE-ORB, JIC-to-metric, and JIC-to-compression adapters are all available. The 37° flare line pairs just fine with Crestflo compression fittings.
Will your JIC fittings interchange with Parker Triple-Lok, Brennan, or Eaton?
Crestflo has no ties to these companies. JIC follows the standardized SAE J514 interface, so a compliant JIC fitting mates by the standard, full stop. If you need a brand-by-part equivalent, ask our engineering team for a cross-reference. Triple-Lok, incidentally, is a trademark held by Parker Hannifin Corporation.
Do JIC 37° fittings come with material certificates?
Yes. EN 10204 MTC 3.1 comes as standard, and we'll supply 3.2 on request. Every part carries its heat or lot number, marked without exception.
Are JIC 37° fittings available for sour service?
Yes. NACE MR0175 / ISO 15156-compliant alloys qualify, including 316/316L, duplex, super duplex, and nickel grades.
Where are your JIC 37° fittings made?
Sourced from India, with US or European melt available on request. Full material traceability comes standard. Standard items ship from ready stock; specials are made to order and take 6-8 weeks.
Related Tube Fittings, Materials & Resources
- Parent line: instrumentation tube fittings
- Related fittings worth a look: 37° JIC flare-fitting family, 45° SAE flare fittings, SAE O-ring boss (ORB) fittings, and NPT-end tube fittings.
- On the materials side, we cover 316/316L, 904L, Duplex 2205, Inconel 625, and Titanium Gr 2.
- Trying to choose between options? Our guides walk through JIC vs ORB, JIC vs DIN 2353, the thread identification guide, and troubleshooting.
- For compliance documentation, see NACE MR0175, EN 10204 MTC, and ASTM F1387.