JIC 37° Flare Fittings: Size Chart, Identification Guide & Comparisons

Need to identify a JIC fitting or source them in volume? This guide covers the full JIC 37° flare size chart from -2 to -32, a step-by-step identification method using calipers and gauges, and how JIC compares with NPT, ORFS, AN and SAE 45° flare fittings. When you know what you need, request a quote and get pricing from qualified hydraulic distributors.

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What Is a JIC 37° Flare Fitting?

A JIC fitting is a hydraulic connector that seals metal-to-metal on a 37° flared seat. The name comes from the Joint Industry Council, which standardized the design; today it is specified by SAE J514 in North America and ISO 8434-2 internationally. JIC is one of the most widely used fitting types in industrial and mobile hydraulics because it is compact, inexpensive, widely available and can be assembled and reassembled many times.

A typical JIC connection has three parts: the male fitting with a 37° flared nose, a female swivel nut, and either a matching 37° seat (on hose ends and adapters) or a flared tube with a sleeve. Threads are straight UNF/UN and only hold the joint together—the seal itself happens on the flare. That is why JIC fittings never need thread tape or sealant.

How JIC dash sizes work

JIC fittings are named by dash size, which equals the tube outside diameter in sixteenths of an inch. A -8 fitting fits 8/16" = 1/2" OD tube. The thread is always larger than the tube: a -8 JIC uses a 3/4-16 thread, not a 1/2" thread. This is the most common source of ordering mistakes.

JIC Fitting Size Chart (-2 to -32)

Thread sizes per SAE J514. Male thread OD is the approximate measurement across the thread crests; measured values run slightly under nominal on worn or plated parts. For a printable version with female thread ID, see our JIC thread size chart.

Dash size	Tube OD	Thread size (UNF/UN)	Approx. male thread OD
-2	1/8"	5/16-24 UNF	0.31" (7.9 mm)
-3	3/16"	3/8-24 UNF	0.38" (9.5 mm)
-4	1/4"	7/16-20 UNF	0.44" (11.1 mm)
-5	5/16"	1/2-20 UNF	0.50" (12.7 mm)
-6	3/8"	9/16-18 UNF	0.56" (14.3 mm)
-8	1/2"	3/4-16 UNF	0.75" (19.1 mm)
-10	5/8"	7/8-14 UNF	0.88" (22.2 mm)
-12	3/4"	1-1/16-12 UN	1.06" (27.0 mm)
-14	7/8"	1-3/16-12 UN	1.19" (30.2 mm)
-16	1"	1-5/16-12 UN	1.31" (33.3 mm)
-20	1-1/4"	1-5/8-12 UN	1.63" (41.3 mm)
-24	1-1/2"	1-7/8-12 UN	1.88" (47.6 mm)
-32	2"	2-1/2-12 UN	2.50" (63.5 mm)

Sizes -3, -5 and -14 are less common and may have longer lead times. -4, -6, -8, -12 and -16 are the most commonly stocked sizes.

How to Identify a JIC Fitting: Step by Step

You need a set of calipers, an inch thread pitch gauge and a seat angle gauge (24°/30°/37°/45°). For a more detailed walkthrough with photos, see How to Identify a JIC Fitting.

Look at the sealing surface. JIC fittings seal metal-to-metal on a 37° cone. The male has a 37° flared nose; the female swivel has a matching 37° seat. There is no O-ring at the sealing face and the threads are straight, not tapered.
Check the angle with a seat gauge. Hold a seat-angle gauge against the nose or seat. A 37° gauge (measured from the centerline) sits flush on JIC. If 45° fits flush, it is SAE 45° flare; if 24°, it is likely metric DIN; a flat face with an O-ring is ORFS.
Measure the thread OD with calipers. Measure across the crests of a male thread or the inside diameter of a female thread. Compare the male OD with the chart: e.g. about 0.75" means 3/4-16, which is a -8 JIC.
Count threads per inch with a thread pitch gauge. Use an inch thread gauge to confirm TPI (24, 20, 18, 16, 14 or 12). Pitch plus OD identifies the UNF/UN thread size.
Confirm straight vs tapered threads. JIC threads are parallel. If the diameter shrinks toward the end and the threads are 27, 18, 14 or 11.5 TPI, you are likely looking at NPT pipe thread instead.
Match to the dash size. Use the chart to convert thread size to dash size. The dash number equals tube OD in sixteenths of an inch, so -8 is 8/16" = 1/2" tube.

JIC vs. Other Fitting Types

JIC vs NPT

NPT (National Pipe Taper) seals on tapered threads and needs sealant; JIC seals on a 37° flare with straight threads and needs none. JIC is easier to reassemble without leaks and handles vibration better; NPT is common on pump and valve ports in older equipment. Read the full JIC vs NPT comparison.

JIC vs ORFS

ORFS (O-Ring Face Seal, SAE J1453 / ISO 8434-3) seals with an elastomer O-ring on a flat face. It is more leak-resistant at high pressure and under vibration, but costs more and the O-ring must be replaced. JIC has no elastomer, tolerates higher temperatures and is cheaper. ORFS threads differ from JIC at each dash size (e.g. -8 ORFS is 13/16-16). See JIC vs ORFS.

JIC vs AN

AN (Army-Navy) fittings use the same 37° flare and thread sizes as JIC, so they mate physically. AN parts are made to tighter aerospace tolerances and Class 3 threads, while JIC uses Class 2. Use AN where AN is specified; JIC is the cost-effective choice for industrial hydraulics. Details in JIC vs AN.

JIC vs SAE 45° flare

SAE 45° flare fittings look similar and several sizes share JIC thread sizes, but the 45° seat will not seal against a 37° seat. SAE 45° is mostly used for low-pressure fuel, refrigeration and automotive lines. Always confirm the angle with a gauge.

Size-specific guides: -4 · -6 · -8 · -10 · -12 · -16 JIC fittings. More comparisons: JIC vs SAE 45° flare, JIC vs BSPP, JIC vs metric DIN 24°. Assembly: JIC torque specs.

Common JIC Materials and Configurations

Materials

Carbon steel (zinc or zinc-nickel plated): the standard for general industrial and mobile hydraulics.
316 stainless steel: for corrosive, marine, food-processing and washdown environments.
Brass: for lower-pressure fluid, fuel and instrumentation lines.

Configurations

Straight adapters: JIC male to NPT, SAE O-ring boss (ORB), BSPP or metric
45° and 90° elbows, including swivel and long-drop versions
Tees, crosses and run tees
Bulkhead unions and bulkhead elbows
Caps, plugs and swivel nuts
Crimp-style JIC female swivel hose ends
Tube nuts and sleeves for flared tube

When requesting a quote, include both ends of an adapter (for example, -8 JIC male × -8 ORB male, 90°), the material and plating, and quantity. Complete specs get faster, more accurate pricing.

See our JIC fitting types guide and JIC materials and pressure ratings.

JIC Fitting FAQ

What does JIC stand for?

JIC stands for Joint Industry Council (often written Joint Industrial Council), the body that originally standardized the 37° flare fitting. Today the design is defined by SAE J514 and ISO 8434-2.

What thread does a -8 JIC fitting use?

A -8 JIC fitting uses a 3/4-16 UNF thread and fits 1/2" OD tube. The dash number refers to tube size in sixteenths of an inch, not the thread size.

Are JIC and AN fittings interchangeable?

They share the same 37° flare angle and the same thread sizes, so they will physically mate. However, AN fittings are built to military aerospace specs with tighter tolerances and higher-class threads, so substituting JIC in aerospace or AN-specified applications is not recommended.

Do I need thread sealant or PTFE tape on JIC fittings?

No. JIC fittings seal on the 37° flare, not on the threads. Sealant or tape does not improve the seal and can contaminate the hydraulic system.

Can JIC fittings connect to NPT?

Not directly. JIC uses straight UNF/UN threads with a flare seal, while NPT uses tapered pipe threads that seal on the threads. Use a JIC-to-NPT adapter.

How is JIC different from SAE 45° flare?

SAE 45° flare fittings use a 45° seat and are mostly used in low-pressure automotive, refrigeration and fuel lines. Several sizes share the same threads as JIC, so always check the seat angle with a gauge—mixing the two will leak.

What materials are JIC fittings made from?

The most common materials are zinc-plated carbon steel, 316 stainless steel and brass. Steel suits general hydraulics, stainless suits corrosive or washdown environments, and brass is used for lower-pressure fluid and instrumentation lines.

How do I get a quote on JIC fittings?

Fill out the request-for-quote form on this page with the fitting type, dash size and quantity. Your request is shared with qualified hydraulic distributors who will respond with pricing and availability.

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