JIC Fittings Guide › -16 JIC Fittings

-16 JIC Fittings: 1-5/16-12 UN Thread for 1" Tube

A -16 JIC fitting is the 37° flare connection sized for 1" (25.4 mm) OD tube. Per SAE J514 and ISO 8434-2 it uses a 1-5/16-12 UN straight thread. The dash number is the tube OD in sixteenths of an inch (16/16" = 1"), not the thread size, which is why a -16 measures larger across the threads than its name suggests. This page covers the dimensions, how to confirm you have a -16, common configurations and what to specify when you order. For every size from -2 to -32, see the main JIC fittings guide.

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-16 JIC Dimensions

Spec	-16 JIC
Standard	SAE J514 / ISO 8434-2
Tube OD	1" (25.4 mm)
Thread	1-5/16-12 UN
Threads per inch	12
Male thread OD (approx.)	1.31" (33.3 mm)
Female thread ID (approx.)	about 1.23"
Seat angle	37° from centerline (74° included)
Typical swivel nut hex	1-1/2" (varies by manufacturer)

Measured values run slightly under nominal on plated or worn parts. Hex sizes are not fixed by the thread size alone, so confirm against the manufacturer's catalog if wrench size matters.

How to Confirm a Fitting Is -16 JIC

Measure the thread OD of a male (or the ID of a female) with calipers. Expect about 1.31" on a male -16.
Check pitch with an inch thread gauge: -16 JIC is 12 TPI.
Check the seat angle with a seat gauge. JIC is 37°; SAE 45° flare and 24° metric cones look similar.
Rule out neighbors. The sizes most often confused with -16 are -14 (1-3/16-12) and -20 (1-5/8-12).

The full process is in our guide on how to identify a JIC fitting.

Common Mix-Ups at -16

SAE 45° flare fittings are rarely used at this size; -16 is overwhelmingly a JIC, ORFS or flange connection in hydraulics. For reference, the ORFS (SAE J1453) thread at the same tube size is 1-7/16-12, so a -16 ORFS nut will not go onto a -16 JIC male. See JIC vs SAE 45° flare and JIC vs ORFS.

Where -16 JIC Is Typically Used

Typical applications include main pressure and return lines on larger mobile and industrial machines, and suction or return lines on power units. Hose dash numbers generally refer to hose inside diameter, and a crimped hose end may carry the same or a different JIC size, so check the hose layline and the fitting separately.

Common -16 JIC Configurations

Male JIC × male JIC straight unions and bulkhead unions
Male JIC × male SAE O-ring boss (ORB) straight, 45° and 90° adapters
Male JIC × male NPT adapters
Female JIC swivel × male JIC adapters, elbows (45°/90°) and tees, including run and branch tees
Caps and plugs, tube nuts and sleeves for flared tube
Reducers to neighboring sizes
Crimp hose ends with female JIC swivel (straight, 45°, 90°)

Descriptions of each shape are in our JIC fitting types guide.

Buying Tips for -16 JIC Fittings

Describe both ends. For example: "-16 JIC male × -16 ORB male, 90° elbow, zinc-plated steel."
Choose material to suit the fluid and environment — zinc-plated carbon steel for most hydraulics, 316 stainless for corrosion, brass mainly for lower-pressure service. See JIC materials and pressure ratings.
Check pressure ratings in the manufacturer's catalog for the exact part and material; elbows, tees and adapters can be rated differently from straight fittings.
Plan assembly. Use the manufacturer's torque or flats-from-wrench-resistance values; our JIC torque specs page explains both methods.

FAQ

What thread size is a -16 JIC fitting?

A -16 JIC fitting uses a 1-5/16-12 UN thread (12 threads per inch) per SAE J514, with a 37° flare seat.

What tube size does -16 JIC fit?

-16 JIC is sized for 1" (25.4 mm) OD tube. The dash number is the tube OD in sixteenths of an inch.

Why does a -16 JIC measure about 1.31 inches?

The dash number describes the tube, not the thread. The 1-5/16-12 UN thread on a -16 JIC measures about 1.31" across the crests.

Is -16 JIC the same as -16 ORFS?

No. -16 ORFS (SAE J1453) uses a 1-7/16-12 thread and an O-ring face seal, so it does not mate with -16 JIC without an adapter.

Can I connect -16 JIC to -16 AN?

Yes in most cases. AN fittings use the same 37° flare and thread sizes, though AN parts are made to tighter aerospace tolerances. Use AN parts where AN is specified.

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