JIC 37° Thread Size Chart

What it is

JIC 37° fittings (SAE J514) seal metal-to-metal on a 37° flare. They use UN/UNF straight threads. The dash number is the tube OD in sixteenths of an inch. A -8 JIC fitting is for 8/16, or 1/2 in, OD tube. JIC is the most common hose end and adapter connection on North American hydraulic equipment.

How to identify

• Look for a 37° cone on the male nose and a matching flare seat in the female swivel. Confirm the angle with a seat gauge.
• Measure the male thread OD with calipers. It reads slightly under the nominal thread OD in the chart.
• Check the pitch with a thread gauge.
• Female swivels are measured across the thread ID, which is smaller than the male OD.

Thread size chart

Measured values run slightly under nominal because of thread tolerances and wear.

Key points

• SAE 45° flare shares some threads with JIC, including -4 (7/16-20), -5 (1/2-20) and -8 (3/4-16). The parts thread together but do not seal. Check the seat angle.
• SAE ORB ports use the same threads as JIC for each dash number. An ORB male has an O-ring at the base of the thread; a JIC male has a 37° nose.
• JIC fittings seal on the flare. Do not use thread tape or sealant.
• Assembly uses a torque or flats-from-finger-tight method. Get the values from the fitting maker.

Common mistakes

• Mixing JIC with SAE 45° parts.
• Calling a fitting -6 because the tube looks like 3/8 in without measuring the thread.
• Over-tightening a JIC joint, which cracks the flare or the nut.

Governing standards: SAE J514 (hydraulic tube fittings); ISO 8434-2 (37° flared connectors); fitting manufacturer assembly data.

Reference only. Verify against the current governing code or standard, the manufacturer's data and the project documents before use. Apps for Distributors disclaims liability arising from reliance on this reference.