1JN Adapter – JIC Male 74° Cone to NPT Male Cross Standard Hydraulic Adapter (SAE J514 / ANSI/ASME B1.20.1)

The 1JN adapter is a straight cross standard adapter that joins a JIC 74° cone male end, made to SAE J514 with an inch straight thread, to an NPT male taper pipe thread made to ANSI/ASME B1.20.1. It is the NPT adapter used where a tube line assembled to the SAE J514 standard has to enter a port or a component that is threaded with American National taper pipe thread.

Both ends must match their mating port exactly, because that match is the precondition for eliminating leakage at the conversion point. The two ends do not seal by the same mechanism: the 74° cone seals metal-to-metal on a cone face, while the NPT end seals on the thread flanks and depends on the thread form plus a sealant to be pressure tight.

Sealing principle of this series: connection 1 is a 74° external cone that seats metal-to-metal on the mating 74° internal cone, and connection 2 is an NPT taper thread where the crests and roots of the thread interfere progressively as the joint is tightened and the helix of the thread closes the leak path.

Ventajas principales

• One body carries an SAE J514 straight thread and an ANSI/ASME B1.20.1 taper pipe thread, so a tube line meets a pipe port without an extra reducer.
• Two sealing systems on one part: a metal cone joint at the tube end and a thread-flank joint at the pipe end.
• Wide spread from a 5/16″x24 JIC end to a 2.1/2″x12 JIC end, and from Z1/8″x27 to Z2″x11.5 on the NPT end.
• Reducing and expanding rows in the printed table, so the pipe port size is chosen independently of the JIC size.
• Centre hex from 12 mm to 65 mm across flats, so standard wrenches fit without special tooling.
• Carbon steel with trivalent chromium zinc plating; 304 or 316 stainless steel available for corrosive service.

1. What a 1JN Adapter Does

A 1JN adapter is a straight stud with a JIC 74° cone male end on one side and an NPT male taper pipe thread on the other. It connects a tube assembly terminated with a JIC 74° cone nut and sleeve to a port or fitting tapped with NPT taper pipe thread.

This JIC adapter does one job: it moves fluid between an SAE J514 tube port and a pipe-threaded port without changing direction. The E column is the JIC 74° cone end, printed in the inch straight-thread style such as 9/16"X18. The F column is the NPT end, printed with the Z prefix and the threads per inch, such as Z1/4"X18. Read the two columns together, because the pipe thread size and the tube size are selected independently and every combination in the table is a valid part number.

The conversion point is where the two sealing philosophies meet. A 74° cone joint needs a clean machined cone and no sealant, while an NPT joint seals on the thread flanks and needs a sealant or an appropriate dryseal thread, so one part asks for two different assembly habits. Section 4 sets out both.

Because the NPT end is a taper thread, the pipe size is chosen for the port rather than to match the tube, which is why reducing rows such as 1JN-08-04 exist.

2. 1JN Specifications

2.1 Connection 1 – JIC 74° cone male end (E)

• Thread standard and family: SAE J514, JIC 74° cone seat family, inch straight thread.
• Thread size range available: 5/16″x24 to 2.1/2″x12, in the steps printed in table 2.5.
• Gender: male adapter stud end.
• Sealing method: 74° external cone seating metal-to-metal on the mating 74° internal cone.
• Mating port standard: SAE J514 74° cone seat, made up with the matching nut and sleeve for the tube.

2.2 Connection 2 – NPT male taper pipe thread end (F)

• Thread standard and family: NPT taper pipe thread to ANSI/ASME B1.20.1, printed with the Z prefix and the threads per inch.
• Thread size range available: Z1/8″x27 to Z2″x11.5, in the steps printed in table 2.5.
• Gender: male pipe thread end.
• Sealing method: pressure-tight joint made on the thread flanks, where the tapered threads interfere as the joint is tightened; a sealant or an appropriate dryseal thread is required, following SAE J476 practice.
• Mating port standard: a port tapped with NPT taper pipe thread, or an NPT female fitting of the same nominal size and pitch.
• Reuse note: an NPT joint is made up once, and a joint that has been loosened is not re-run without re-sealing.

Read the E column as the JIC adapter end in SAE J514 and the F column as the NPT adapter end. The two blocks are mirrored so a buyer can map the tube side and the pipe side of the machine separately.

2.3 Construction and Materials

The body is machined from bar stock on CNC lathes. The straight thread, the taper thread, the 74° cone and the hex are turned in one setup so the cone stays square to its thread and the taper thread runs true to the body axis.

• Body material: carbon steel as standard; 304 or 316 stainless steel on request; brass for selected sizes.
• Plating and finish: trivalent chromium zinc plating (Cr3+) for carbon steel as standard; zinc-nickel plating available. Plating thickness and corrosion performance are confirmed per order rather than published as a series figure.
• Seal material options: the 74° cone joint is metal-to-metal and carries no elastomer. Where the same circuit uses elastomer-sealed components, NBR, FKM and EPDM are the available seal compounds.
• Thread sealant: the NPT end seals on the thread flanks, so a compatible thread sealant is applied at assembly; it is a field consumable, not supplied with the part.
• Machining process: bar-stock turning, the taper thread produced to its port standard, the cone checked against the drawing.
• Hex feature: one centre hex (S1), from 12 mm to 65 mm across flats. There is no bulkhead feature in this series.

2.4 Pressure and Temperature

Working pressure for a 1JN adapter is not set by the series code. It is governed by the thread size, the wall thickness of the stud and the tube, the sealing method and the material selected. It is confirmed per order by HENGHUA engineering.

Temperature is a material question and is stated here as a material fact rather than a performance claim. For NBR seals, the working range is approximately -30°C to +100°C. For FKM (Viton-type) seals, it is approximately -20°C to +200°C. For EPDM seals, it is approximately -40°C to +120°C. These figures apply to the elastomer-sealed components of the circuit, because neither end of the 1JN body contains an elastomer.

2.5 Part Number and Dimension Table

The table below is the complete printed size range of the 1JN series; lengths and hex dimensions are in millimetres.

What each column means

• PART NO. – the HENGHUA part number: the series prefix 1JN followed by one JIC size code, or by a JIC size code and an NPT size code separated by a dash.
• E – the thread of connection 1, the JIC 74° cone end, printed as diameter x threads per inch in the SAE style, for example 7/8"X14.
• F – the thread of connection 2, the NPT taper pipe thread, printed with the Z prefix and the threads per inch, for example Z3/8"X18.
• A – the length from the end of connection 1 (the JIC cone end) to the hex face on that side, in millimetres, as marked on the series drawing.
• B – the same measurement at connection 2 (the NPT end), in millimetres, taken to the small end of the taper.
• L – the overall length of the part from end to end, in millimetres.
• S1 – the hex across flats, in millimetres, used to hold the body while the pipe end is run in.

Thread size and dash chart

The JIC size code follows the SAE convention based on the nominal tube outside diameter in sixteenths of an inch. The NPT end is printed directly with the Z prefix.

Nut and sleeve are ordered separately. The 1JN stud does not include them. Use nut NB200 with sleeve NB500 for metric tube and with sleeve NB300 for inch tube.

3. How to Read a 1JN Part Number

A 1JN part number has three elements: the series prefix, the JIC size code and, when the NPT size differs from the standard pairing, the NPT size code.

The prefix 1JN identifies the geometry and the thread pair: a straight stud with a JIC 74° cone male end and an NPT male taper pipe end. Other prefixes cover a metric male end, a metric captive seal end or a BSP male end.

The first size code is the JIC end, taken from the SAE dash convention. When only one code is printed, for example 1JN-06, the part is the standard pairing of that JIC size with the corresponding pipe thread, printed in the F column. When two codes are printed, the second one is the NPT size, so 1JN-06-04 pairs a 9/16″x18 JIC end with a Z1/4″x18 NPT end.

Worked example: 1JN-08-12.

• 1JN – straight stud, JIC 74° cone male to NPT male.
• 08 – connection 1 is the SAE J514 size with a 3/4″x16 thread.
• 12 – connection 2 is the NPT end with a Z3/4″x14 thread.
• From the table: A is 16.7 mm, B is 19.5 mm, L is 46.5 mm, S1 is 30 mm.

A buyer ordering 1JN-08-12 therefore receives a male adapter whose JIC end takes a 3/4″x16 tube assembly and whose NPT end runs into a Z3/4″ port. Check the pipe thread against the tapped port before ordering, because the pipe size follows the port.

4. Installation and Fitment

The two ends of a 1JN adapter are assembled by different rules. The JIC end is a cone joint, tightened until the cone seats metal-to-metal. The NPT end is a taper thread joint, run in until the threads are engaged over the full working length and the sealant has filled the helix. HENGHUA does not print a single torque figure for this hydraulic adapter, because the correct tightening depends on the mating nut and port, the tube material and the wall thickness.

Cone seat handling: keep the 74° cone and the mating JIC seat clean and free of nicks. Wipe the cone with a lint-free cloth and inspect it under good light. An overtightened cone is deformed and must be replaced.

NPT thread preparation: apply a thread sealant compatible with the fluid to the male taper thread, leaving the first one or two threads bare so the sealant cannot enter the circuit. Do not use thread tape on a hydraulic NPT joint unless the tape is rated for the fluid and applied in the correct direction, because a loose strand can travel into a valve. Where the port is machined for a dryseal thread to SAE J476, the port specification governs.

Contamination control: cap open ends before storage and before the line returns to service, because debris that reaches the cone scores the seat and debris in the pipe thread is pushed into the fluid path.

Alignment: bring the tube squarely to the cone end before starting the nut, and start the pipe end by hand to confirm the thread is not crossed. Because the NPT end must be run in to a depth, check the finished orientation of the body before final tightening.

Reuse policy: the stud body with an undamaged cone and a sound pipe thread can be reused. The nut and sleeve are wear items, and a broken NPT joint must be cleaned and re-sealed before remaking.

Common fitment errors and their symptoms:

• Wrapping the JIC 74° cone threads with tape. Symptom: the cone never seats squarely and the joint weeps at first pressure.
• Reusing an NPT joint without re-sealing. Symptom: a weep along the thread helix.
• Interchanging NPT with BSPT. Symptom: the joint starts by hand and then binds, because the thread angles and pitches differ.

Six-step assembly

1. Confirm the part number against the line list, checking the JIC cone end and the tapped port size and pitch.
2. Inspect the cone, the mating seat and the pipe thread for nicks, corrosion and overtightening marks.
3. Clean the cone and both threads, and confirm the sealant suits the fluid.
4. Fit the nut and sleeve to the tube, then bring the tube square to the cone end by hand.
5. Run the pipe end in by hand first, apply sealant, then tighten it to working engagement; tighten the JIC nut in stages until the cone seats.
6. Pressurise the circuit, check both ends for weeping, and re-check tightness after the first thermal cycle.

5. Applications and Industries

Application tags for this series: hydraulic systems, water jetting, oil and gas, industrial equipment, construction machinery, agriculture, marine, material handling.

Cross-standard equipment integration. A machine can carry SAE J514 tube assemblies while its pumps, valves and cylinders are fitted with NPT pipe ports. This 1JN adapter provides the interface the two sides need, and the printed table lets the pipe size follow the port while the tube size follows the line.

Repair and replacement. Maintenance crews fit this series when a pipe-threaded component has to be joined to an existing tube run, or when a damaged stud is replaced on site. Because the table spans twelve JIC sizes against nine NPT sizes, the part is usually drawn from stock.

High-pressure test benches. Test rigs mix tube lines with pipe-threaded gauges and needle valves. The cone end gives a repeatable metal-to-metal seat that can be remade, while the pipe end gives a sealed joint on the threads.

6. Replacement and Cross-Reference Guide

Cross-reference for this series is organised by standard and sealing method, never by brand. Two fittings interchange only if the standard, thread size, seat angle and seal type match.

A 1JN adapter is a JIC adapter with an SAE J514 74° cone stud at one end and an NPT taper thread to ANSI/ASME B1.20.1 at the other. It is not interchangeable with a JIC 37° flare fitting, which seals on a 37° conical flare face, and it is not interchangeable with an ORFS fitting, which seals a flat face against an elastomeric O-ring under SAE J1453. The pipe end is also not interchangeable with BSPT: BSPT is a 55° taper thread under ISO 7-1 and NPT is a 60° taper thread, so the two will not seal even where the nominal sizes correspond.

To identify the correct replacement, measure three things.

1. Thread at both ends. Measure the outside diameter and the pitch at each end separately. A 9/16″ end measures about 14.3 mm outside diameter with 18 threads per inch, while a Z1/4″ pipe thread measures about 13.7 mm with the same 18 threads per inch: similar readings, different families.
2. Taper at the pipe end. Check the thread with a pitch gauge against a known NPT thread: a 60° form with the NPT pitch confirms NPT, while a 55° form points to BSPT or BSPP.
3. Seal type at the tube end. Confirm whether the tube end seals on a metal cone or on an elastomer. The 1JN tube end is a metal cone joint with no O-ring in the sealing path.

Where the tube port is an ORFS or a flange connection, a different cross standard adapter is the correct part rather than a forced thread, and HENGHUA can match the replacement from the printed table.

7. Ordering, Packaging and Delivery

To order, give the following information:

• Series code: 1JN.
• Full part number, for example 1JN-10-08, taken from table 2.5.
• Thread sizes for the JIC end and the NPT end, read from the E and F columns, including the threads per inch.
• Nut and sleeve requirement for the tube (nut NB200 with sleeve NB300 for inch tube), ordered separately.
• Seal material (NBR, FKM or EPDM) for the elastomer-sealed components, plus body material and plating: carbon steel with trivalent chromium zinc plating, zinc-nickel plating, or 304 or 316 stainless steel.
• Quantity, destination and packing format required.

Packaging formats: bulk cartons for line-side consumption, small boxes for distributor shelves and labelled bags for service kits, each labelled with the part number and both threads.

Sample orders: validation and first-article parts are available for OEM programmes, including specials outside the printed table.

Lead time for the 1JN adapter is confirmed per order, because it depends on the size, the material, the plating and the quantity. As a hydraulic adapter manufacturer and hydraulic adapter supplier, HENGHUA can quote the stud, the nut and the sleeve as one matched kit.

8. FAQ

What is the difference between JIC 37° flare and ORFS, and which should I use?

A JIC 37° flare joint seals metal-to-metal on a 37° conical flare face under SAE J514. An ORFS joint seals a flat face against an elastomeric O-ring under SAE J1453. Choose the family that matches the port on the equipment, because the two are not interchangeable. The 1JN series is on the JIC 74° cone side of SAE J514, with an NPT taper thread at the pipe end.

Can NPT and BSPT be interchanged?

No. NPT is a 60° taper pipe thread under ANSI/ASME B1.20.1, and BSPT is a 55° taper pipe thread under ISO 7-1. The thread form, the angle and the pitch differ, so the two will not seal even though some sizes start by hand. The 1JN pipe end is NPT, so a BSPT port needs a different cross standard adapter.

How do I identify the correct 1JN size?

For an NPT adapter, measure the outside diameter and the pitch at each end and read across the E and F columns of table 2.5. When the JIC straight thread and the pipe thread both match a printed row, that row is the correct part number. The pipe size follows the tapped port, so do not assume it matches the tube size.

What seal material should I select for my fluid and temperature?

For mineral hydraulic oil within -30°C to +100°C, NBR is the usual choice. For higher temperatures up to approximately +200°C, or where the fluid attacks NBR, choose FKM (Viton-type). For water-based fluids, EPDM is the option, with a working range of approximately -40°C to +120°C. In this series the choice applies to the elastomer-sealed parts of the circuit, and the thread sealant must suit the fluid and temperature as well.

How is the working pressure of this adapter determined?

Working pressure is not fixed by the series code. It is governed by the thread size, the wall thickness of the stud and the tube, the sealing method and the material selected, and is confirmed per order by HENGHUA engineering.

What is the minimum order quantity and can I get samples?

Minimum order quantity depends on the size code, the material and the plating, so it is confirmed with the quotation. Samples are available.

Which end should be tightened first?

Run the pipe end in first while the body can still be turned by its hex, then hold the body and tighten the JIC nut to seat the cone; tightening the cone first can pull the pipe end out of engagement.

Send your requirement to HENGHUA

Send the part number, the JIC thread, the NPT thread, the nut and sleeve requirement, the material and plating, and the quantity. HENGHUA confirms the match to the printed table, the seal options and the delivery schedule, and quotes the 1JN adapter that fits your circuit.

Related series in the same family: the 1J adapter (straight) and the 1JN9 adapter (90° elbow). Browse the full Hydraulic Adapters range for the complete SAE J514 JIC, NPT, ORFS and ISO 6162 flange families.