Hydraulic Fitting Sizes & Torque — JIC, ORFS, ORB, AN

Identify Your Fitting First

Four hydraulic fitting families look similar at a glance but seal differently and are not interchangeable, even at the same dash size:

• JIC 37° flare (SAE J514) — a 37° cone seals metal-to-metal against a matching flare. No O-ring. The most common hydraulic hose-end fitting.
• ORFS — O-ring face seal (SAE J1453) — a flat face with a captured O-ring seals against a matching flat face. No cone, no metal-to-metal seal.
• ORB — O-ring boss (SAE J1926) — a straight (non-tapered) thread screwed into a port, sealed by an O-ring at the base. A port connection, not a hose-to-hose joint.
• AN — the aerospace/military and performance-aftermarket twin of JIC: same 37° flare, same thread series, same tube-nut wrench sizes (AN818).

Watch for mislabeled charts: some widely-circulated fitting charts print JIC thread sizes under an "ORFS" heading. If a chart's "-6 ORFS" row lists a 9/16-18 thread, that's the JIC thread series under the wrong heading — the real -6 ORFS thread, confirmed independently by Parker, Eaton, and Surplus Center, is 11/16-16. Confirm which family a chart actually describes before you buy a fitting or a wrench.

JIC 37° Flare (SAE J514) — Sizes, Wrench & Torque

Torque figures combine every dry-steel torque recommendation found from Parker (Table T20, +10%/−0%), Brennan Industries / Surplus Center, Hose & Fittings Etc., Gates, Eaton Aeroquip, and Apex Flow Solutions — manufacturers do not agree on JIC torque, so the range shown spans every published number for that dash. Gates states its own SAE J514 values "are for qualification testing only and should not be used as the basis for setting up torque values." Prefer your fitting manufacturer's own chart when you have one, and reduce torque for lubricated, plated, or brass fittings.

FFWR (flats past wrench resistance): finger-tighten the nut, then turn it further with a wrench until it stops moving easily — that's the "wrench-resistance" point (about 30 in-lb, per Hose & Fittings Etc.). From there, turn the extra number of flats shown; 1 flat = 1/6 of a turn. -20, -24, and -32 agree at exactly 1 flat across every source; smaller dashes vary by manufacturer, so the range shown is the full published spread — use FFWR instead of a torque number whenever threads are lubricated, oily, or the fitting is stainless steel or brass. † -14's 1 3/8 in wrench is published by Parker only — AN818 has no -14 entry to cross-confirm against.

AN Fittings (Aerospace / Performance 37° Flare) — Sizes & Torque

AN818 defines the tube-coupling-nut hex (the "P" dimension); AN and JIC share the same 37° flare thread series, so a JIC and an AN nut of the same dash use the same wrench. Hose-end hex sizes on AN hose fittings are NOT standardized — Pegasus explicitly declines to publish them, and one common -3 AN aluminum hose end uses a 1/2 in hex despite the tube-nut standard being 7/16 in.

Aluminum and stainless figures are confirmed across independent sources (Holley, Pegasus, Summit Racing/OnAllCylinders, and the Van's Aircraft/AN Plumbing tech sheet). The Steel column is published by Pegasus only — no other source in this review lists AN steel torque separately. When an aluminum fitting mates to a steel or stainless one, use the aluminum torque value — aluminum is the weaker material and controls the joint. Quarter-turn method: hand-tighten until the flare seats, then turn the nut an additional quarter turn — about 1.5 hex flats — confirmed for all AN dash sizes across independent sources.

† -32 stainless: Holley publishes 2660-2940 in-lb; Summit Racing/OnAllCylinders publish an equivalent 188-245 ft-lb (2256-2940 in-lb) — shown as the combined range since the published minimums differ.

ORB — O-Ring Boss (SAE J1926) — Sizes & Torque

An unlabeled ORB torque number is ambiguous by roughly 2x. Manufacturers publish two distinct torque series for the same dash, and a chart that gives one number per dash without saying which regime it means could be citing either — check your fitting's stud type and your system's rated pressure before torquing it.

Light-duty covers JIC/NPTF/NPSM-stud ORB fittings (SAE J1926/3 & J514) — this is the series John Deere's OEM operator-manual chart tracks. Heavy-duty covers ORFS-stud ORB fittings (SAE J1926/2 & J1453) — Gates and Eaton Aeroquip publish identical numbers for this series across every dash they share. There is no standardized ORB wrench size: torque is applied to the fitting body's own hex (straight fittings) or to the locknut (adjustable fittings), and that hex varies by manufacturer and fitting design — check the fitting itself. Lubricate the O-ring and threads before assembly (Parker, John Deere). Parker's chart also notes: use the upper end of the range for stainless steel fittings, and reduce torque by roughly 35% for brass.

† -2 light-duty torque is published by Tompkins/Midland only.

ORFS — O-Ring Face Seal (SAE J1453) — Sizes, Wrench & Torque

Wrench sizes are Parker's tube-nut hex only — hose-end swivel-nut hexes can be larger (one -6 ORFS hose fitting lists a 7/8 in / 22 mm hex against Parker's 13/16 in tube nut). ‡ -5, -14, and -32 are Parker catalog extensions — SAE J1453 itself standardizes only -4 through -24, skipping -5 and -14.

Eaton Aeroquip and Surplus Center publish an agreeing torque series for ORFS assembly. Parker's own Table T14 publishes a distinctly higher "wet-torque" series for the same fittings — Parker's assembly instructions call for lubricating the O-ring and threads before assembly, which is a documented reason two manufacturer specs for the same fitting differ this much. Do not rotate the fitting body while tightening the nut.

† -14 torque (65-80 ft-lb) is published by Gates only; Eaton and Surplus Center do not list a -14 ORFS value.

What size wrench do I need for a -6 JIC fitting?

An 11/16 inch wrench on the tube nut, across flats — confirmed by both Parker’s tube-nut hex table and the AN818 tube-coupling-nut standard. A -6 JIC fitting has a 3/8 inch tube OD and a 9/16-18 thread.

What size wrench do I need for a -6 AN fitting?

Also 11/16 inch, per AN818. AN and JIC share the same 37-degree flare thread series, so a -6 AN tube-coupling nut and a -6 JIC tube nut use the same thread (9/16-18) and the same wrench. Hose-end AN fittings are a separate case — hex sizes on AN hose ends are not standardized and can differ from the tube-nut chart.

What size is a -6 ORFS fitting, and why do some charts disagree?

A -6 ORFS fitting is an 11/16-16 thread on a 3/8 inch tube, per Parker and Eaton. Some published charts list 9/16-18 for "-6 ORFS" — that number is actually the JIC thread series, printed under the wrong heading. If a chart’s ORFS column matches its JIC column exactly, treat it with suspicion.

How much torque does a -6 JIC fitting need?

Published manufacturer recommendations for a dry, unlubricated steel -6 JIC fitting range from about 12 to 22 ft-lb, depending on the source — Parker, Brennan/Surplus Center, Hose & Fittings Etc., Gates, Eaton Aeroquip, and Apex Flow Solutions all publish different numbers for the same physical fitting. Use your fitting manufacturer’s own chart when you have one, and reduce torque for lubricated or plated threads.

What wrench size fits an ORB (O-ring boss) fitting?

There isn’t a standard one. SAE J1926 standardizes the port thread, not a swivel nut — torque is applied to the fitting body’s own hex on straight fittings, or to the locknut on adjustable fittings, and that hex size varies by manufacturer and fitting design. Check the specific fitting or its datasheet rather than a generic chart.

How do I torque an AN fitting without a torque wrench?

Hand-tighten until the flare seats, then turn the nut an additional quarter turn — about 1.5 hex flats. This rule is confirmed across independent sources and applies to every AN dash size. If you’re mating an aluminum fitting to a steel or stainless one, torque to the aluminum value — aluminum is the weaker material and controls the joint.

When should I use the flats method instead of a torque spec?

Use flats-past-wrench-resistance instead of a torque number whenever the threads are lubricated or oily, the plating is mixed or unknown, or the fitting is stainless steel or brass — published torque values assume clean, dry steel threads and are not reliable outside that case, per Parker’s own assembly notes.