Schematic cross-section of the male half, upper side only, with the centre line dashed and the open end on the left. Cone angles are drawn at their true angle from the axis; nothing else is to scale and no dimension should be measured off it. Thread shown: 1-14 UNF.
A completely flat male nose with a shallow O-ring groove machined into the face, and a flat female face with no groove at all.
Where it seals: The O-ring squashed between the two flat faces. The thread only holds the load.
Dimensions
Thread size, pitch and diameters for -10 ORFS.
Designation
-10 ORFS
Thread
1-14 UNF
Threads per inch / pitch
14 TPI (1.814 mm pitch)
Basic major diameter (male)
25.4 mm / 1 in
Measured across the male crests
25.3 mm to 25.4 mm
Basic minor diameter (mating female)
23.44 mm / 0.923 in - computed from the 60 degree thread profile, not measured
Thread form
60 degree flank angle, parallel
Seat
O-ring face seal (flat face)
Tube outside diameter
0.625 in (15.88 mm)
O-ring
AS568-016
How the size is named
Sized by dash number for the tube outside diameter, but the thread is larger than the JIC thread of the same dash.
Working pressure
Published working pressure6,000 psi (414 bar)
This figure applies only under these conditions: Steel fitting at a 4 to 1 design factor against minimum burst per SAE J1453. The higher figure is a straight (non-adjustable) port stud, the lower an adjustable stud. Both publishers give the same pair. Proof pressure is twice the working figure and minimum burst four times it, per the same table.
A fitting with two different ends is only ever as strong as the weaker end, and any rating assumes the fitting is undamaged, correctly assembled and within its temperature range. Pressure ratings are safety-relevant: confirm them against the manufacturer specification before the system is charged.
What it mates with
A female 1-14 UNF ORFS swivel with a flat face and no groove, on the same dash size. The O-ring in the male face is the seal.
Missing or pinched O-rings are the only common failure on this connection. The male face must be clean and undamaged; a nick across the groove will weep no matter how hard the nut is pulled up.
Do not mix these up
Fittings that measure like a -10 ORFS
Every size below sits within 0.9 mm of this one across the male thread crests, which is inside what a worn or plated fitting and a hurried measurement produce together. Those marked same thread will screw together with this fitting.
Fittings in other standards whose male thread diameter is close to -10 ORFS.
No - 0.6 mm apart on diameter, and a different pitch
This list is computed from the published diameters in the database rather than kept as a hand-written list, so a correction to a table can never leave a stale warning behind.
Answers
Common questions about -10 ORFS
What thread is a -10 ORFS fitting?
-10 ORFS runs a 1-14 UNF thread: 14 TPI (1.814 mm pitch), basic major diameter 25.4 mm / 1 in. Published identification charts read 25.3 mm to 25.4 mm across the male crests, which is the figure a caliper produces.
How do I tell a -10 ORFS apart from a fitting that measures the same?
Look at the sealing surface. A completely flat male nose with a shallow O-ring groove machined into the face, and a flat female face with no groove at all. The O-ring squashed between the two flat faces. The thread only holds the load. The thread is parallel (straight) and the flank angle is 60 degrees.
What does a -10 ORFS screw into?
A female 1-14 UNF ORFS swivel with a flat face and no groove, on the same dash size. The O-ring in the male face is the seal.
What pressure is a -10 ORFS rated for?
6,000 psi (414 bar). Steel fitting at a 4 to 1 design factor against minimum burst per SAE J1453. The higher figure is a straight (non-adjustable) port stud, the lower an adjustable stud. Both publishers give the same pair. Proof pressure is twice the working figure and minimum burst four times it, per the same table.
What size O-ring does a -10 ORFS take?
AS568-016. The O-ring is the seal on this connection - the thread only carries the load - so a missing, pinched or wrong-size ring leaks no matter how hard the joint is pulled up.
Dimensions are as defined by SAE J1453, ISO 8434-3. FittingKey is an independent reference and is not affiliated with, endorsed by or approved by any standards body or fitting manufacturer.
Every value on this page was checked against 7 independent published sources:
Which published source supplied each column, and what it gave.
Column
Sources
What they gave
Dash and trade size
tompkins, mcgill-id, gageref-orfs, chs-orfs
Four publishers agree the series runs -04 to -24. One adds a -14 and a -32 that no other source carries; both are recorded as gaps rather than published.
Basic major diameter
tompkins, mcgill-id
The thread designation fixes the basic major diameter: a 3/4-16 UNF thread has a basic major diameter of 0.750 in, which is 19.05 mm at 1 in = 25.4 mm exactly. The inch and millimetre columns are that one figure in two units.
Measured male thread diameter
apex-threadid, mcgill-id
Two identification charts. A third prints 22.0 mm at -08, which fits neither the thread nor its own female figure, and is recorded as a disagreement instead of being averaged in.
O-ring size
globaloring, chs-orfs
The AS568 zero-series dash numbers are identical in both: 011, 012, 014, 016, 018, 021, 025 and 029.
Working pressure
tompkins, brennan-pressure
Two catalogues, steel, 4 to 1 against minimum burst per SAE J1453, straight and adjustable studs given separately. Both pairs match on all eight sizes.
Sources disagree: ORFS -08 male thread diameter.
22.0 mm (gates-idchart)
20.6 mm (apex-threadid)
20.8 mm (mcgill-id)
22.0 mm cannot be a 13/16 in thread, whose basic major diameter is 20.64 mm, and the same chart gives a female inside diameter of 19.1 mm, which only fits the smaller figure. The outlier is treated as a misprint and excluded from the published span, and it is recorded here so nobody has to work that out twice.