4J JIC Male 74 Degree Cone Plug – JIC 74 Degree Cone Blanking 4J Adapter

A 4J adapter is a JIC male 74 degree cone plug, a blanking device that closes a JIC female 74 degree seat port with a male 74 degree cone and a closed body. It has no second port and no through passage, so nothing flows through it: the plug seals the port by the same 74 degree cone metal seat principle that an ordinary JIC adapter uses at that end, and simply stops the line there. One threaded cone stud end, one closed end, and a wrench hex between them is the whole part.

Principais vantagens

• Closes a JIC female 74 degree seat port with the same metal-to-metal cone seat the port was designed for.
• No through passage and no second port, so a spare or unassigned port can be blanked with one part.
• No O-ring and no thread sealant at the seat, so there is no elastomer to select or to age.
• Eleven published dash sizes from 7/16″X20 to 2.1/2″X12, matching the SAE J514 74 degree seat family.
• Hex S1 between the cone and the body gives a full wrench flat for tightening and for removal.
• Carbon steel with trivalent chromium zinc plating, or 304 / 316 stainless steel for corrosive service.

1. What a 4J Adapter Does

The 4J adapter is a hydraulic plug adapter that closes a port. It is a JIC male 74 degree cone plug: one end carries the familiar male 74 degree cone and united fine thread, and the rest of the part is a solid machined body with a hex between the two. Where a normal adapter joins two lines, this one ends a single line, so it belongs to the blanking group of the catalogue together with the flange plugs and the female seat plugs rather than to the conversion group.

Both sides of the joint still have to match exactly. The thread size, the thread pitch and the 74 degree cone angle of the plug have to agree with the female seat port it is turned into, because that agreement is the precondition for eliminating leakage at the plugging point. A plug that starts easily but reaches seat contact at the wrong depth is the wrong dash size, and a plug whose cone does not meet the seat face will weep no matter how much it is tightened.

The sealing principle of this series is the 74 degree cone metal seat. The male cone on the plug seats against the wide cone face machined inside the female port, and the joint is metal-to-metal, exactly as it would be if a JIC male 74 degree cone stud end were fitted there. The 4J adapter does not seal on a 37 degree flare, on an O-ring, on a flat face or on tapered pipe threads, and there is no elastomer anywhere in the joint. Because the body is closed, the joint sees pressure on one side only, and the plug is loaded by the system pressure as a static blanking element rather than as a flow path.

Where a port has to be closed, the choice between a solid plug such as this one and a hollow hex plug is a question of access and of profile. A solid plug such as the 4J needs wrench clearance around the port, so it suits an open port face and a large dash size.

2. 4J Specifications

The two ends of this series are described below as a mirrored pair: the connection to the port, and the closed end that carries the hex.

2.1 Connection 1 – JIC male 74 degree cone, external thread E

• Thread standard and family: SAE J514, SAE 74 degree seat and flareless family. The thread form is the unified fine thread used by the JIC 74 degree cone stud end of the same dash size.
• Thread sizes available at E: 7/16″X20, 1/2″X20, 9/16″X18, 3/4″X16, 7/8″X14, 1.1/16″X12, 1.3/16″X12, 1.5/16″X12, 1.5/8″X12, 1.7/8″X12 and 2.1/2″X12.
• Gender: male stud end (external thread) with a formed 74 degree cone at the nose.
• Sealing method: metal-to-metal contact between the 74 degree cone of the plug and the 74 degree seat face of the female port. No O-ring, no bonded washer and no thread sealant is used at this joint.
• Mating port standard: a female 74 degree seat port of the same dash size and thread, as defined in the SAE J514 74 degree seat family, such as the female port of a 2J, 9J or DJ type connection.
• Wrench feature: hex S1 behind the cone gives the flats for tightening the plug into the port and for removing it again.

2.2 Connection 2 – Closed blanking end, no port and no through passage

• Connection type: closed. The body ends in a solid, turned shank, so there is no second thread, no second seat and no bore through the part.
• Sizes available: all eleven published rows are closed; every 4J part number is a blanking plug and none of them passes flow.
• Gender: not applicable, because no mating part is fitted at this end.
• Sealing method: not applicable at this end. Sealing takes place entirely at the 74 degree cone in 2.1. The closed end has no sealing face, no O-ring groove and no cap.
• Mating part standard: not applicable. What is required at that side of the plug is clearance for the body, and access for the wrench and for the hex S1 flats.

2.3 Construction and Materials

• Body material: this steel hydraulic adapter is offered in carbon steel, 304 stainless steel, 316 stainless steel or brass, selected per order.
• Plating: trivalent chromium zinc plating (Cr3+) or zinc-nickel plating on carbon steel bodies. Stainless steel bodies are supplied without plating.
• Cone form: the male 74 degree cone is formed at the nose of the stud end and is machined in the same set-up as the thread where the process allows, so the cone runs true to its thread.
• Seal material: as a steel hydraulic adapter this plug carries no elastomeric seal, no O-ring and no bonded washer. The 74 degree cone is a metal-to-metal joint, so there is no elastomer to select and no elastomer to age. Where an O-ring is used elsewhere in the same circuit, the published material ranges are approximately -30°C to +100°C for NBR, -20°C to +200°C for FKM and -40°C to +120°C for EPDM.
• Machining process: the plug is turned from bar stock on CNC lathes, the cone and the external thread are cut, the hex is milled or formed, and the part is deburred. Threads are gauged with ring and plug gauges, and the cone form, the hex and the overall length are checked against the drawing batch by batch before packing.

2.4 Pressure and Temperature

Temperature is governed by the body material, because this hydraulic adapter carries no elastomeric seal. A carbon steel body with zinc plating suits general hydraulic service, and 304 or 316 stainless steel is selected for corrosive environments. Where a seal material question arises elsewhere in the same circuit, the published material ranges are approximately -30°C to +100°C for NBR, -20°C to +200°C for FKM and -40°C to +120°C for EPDM elastomers.

Working pressure for a given 4J size is confirmed per order by HENGHUA engineering, based on the thread size, the body wall thickness, the sealing method and the material selected. No single pressure figure is published here for a specific size, because a 7/16″X20 plug and a 2.1/2″X12 plug do not share one rating. A blanking plug also differs from an adapter in service: it holds pressure on one side only and is not subject to flow-induced load, but it is often left in place for long periods, so the fluid and the ambient conditions at the port belong in the same review.

2.5 Part Number and Dimension Table

The table below is the complete published dimension table for the 4J JIC adapter series. Every row is reproduced in printed column order.

Note on the mating side: the nut and the sleeve are ordered separately. Nut NB200 with sleeve NB500 suits metric tube, and nut NB200 with sleeve NB300 suits inch tube.

What each column means:

• PART NO. is the ordering code. The dash number is the dash size of the JIC 74 degree seat thread carried at E.
• E is the external thread of the male 74 degree cone plug end, written in catalogue notation. The fraction and the number after X give the thread size and the pitch in threads per inch, so 9/16″X18 is a 9/16″ unified fine thread at 18 threads per inch.
• A is the plug end dimension in millimetres, measured from the cone face to the hex, as marked A on the series drawing. It fixes how far the threaded end projects into the port before the hex is reached.
• L is the overall length of the plug in millimetres, from the cone face to the outer end of the body.
• S1 is the width across flats of the hex on the plug body, in millimetres. It is a wrench size, not a thread size, and it grows with the dash size.

Thread size and dash chart:

3. How to Read a 4J Part Number

The 4J part number has two parts: the series prefix and the dash size.

• 4J is the series prefix. It identifies the part of this page: a JIC male 74 degree cone plug with a closed body, as listed in this table.
• The dash number is the size code. It follows the SAE J514 dash convention, in which the number is the nominal tube outside diameter in sixteenths of an inch: 04 means 4/16″ or 1/4″, 06 means 3/8″, 08 means 1/2″, 12 means 3/4″, 16 means 1″ and 32 means 2″.
• The dash size fixes the thread, not the tube size alone. 4J-08 carries a 3/4″X16 thread, which is the thread used by the 1/2″ dash in the 74 degree seat family.
• No suffix is applied to any row in the 4J table. Other series in the same catalogue use suffixes such as -SP, -WD or -PK to mark a variant of that series; if a suffix appears on your drawing, quote the full part number including it.

Worked example using a real row of the table. Part number 4J-08 decodes as follows:

• Series: 4J, JIC male 74 degree cone plug.
• Thread E: 3/4″X16 external thread with a 74 degree cone, the dash 08 size of the 74 degree seat family.
• Plug end dimension A: 16.7 mm from the cone face to the hex.
• Overall length L: 25 mm, and wrench hex S1: 22 mm.
• Function: it closes a single female 74 degree seat port and passes no flow.

4. Installation and Fitment

A 74 degree cone joint is made by drawing the male cone into the female seat until the two metal faces meet. Tightening is a feel-and-angle operation: bring the plug in finger-tight, snug it with a wrench, and continue only as far as the port specification requires, because once the cone face is fully seated no further tightening improves the seal.

Keep the cone face and the seat clean and free of burrs and old sealant. A 74 degree seat seals on machined metal faces, and a single nick or a trapped chip will produce a weep that no amount of tightening will remove. Do not apply PTFE tape or liquid sealant to the cone; sealant belongs on tapered pipe threads, not on this joint, and a film of it will hold the cone off its seat.

Reuse is a practical question rather than a rule of thumb. A 4J adapter can be refitted if the cone face is still smooth, unmarked and free of corrosion, and if the thread is undamaged. A plug whose cone has been deformed by over-tightening, or whose thread has been cross-started, is not restored by tightening it harder; replace it. Assembly steps:

1. Confirm that the port is a female 74 degree seat port of the same dash size and thread as E, and that it is not a 37 degree flare port, an O-ring boss port or a tapered pipe port.
2. Inspect the cone face of the plug and the seat face of the port for nicks, burrs, corrosion and trapped debris.
3. Clean the thread and the cone, and remove any old sealant or tape from the port thread.
4. Turn the plug in by hand until the cone touches the seat, checking that it starts square and does not cross-thread.
5. Snug the plug with the correct wrench on hex S1, stopping when the cone is seated, and note the wrench position so a re-check can be made later.
6. Leak-check the blanked port at the pressure agreed for the system, and confirm that the plug body clears any adjacent fitting or tube.

Common fitment errors and their symptoms:

• Fitting a plug of the wrong dash size. The symptom is a thread that starts by hand but reaches seat contact at the wrong depth, so the hex sits proud or the body bottoms before the cone seats.
• Applying thread sealant or PTFE tape to the cone. The symptom is a joint that will not seat and a cone face contaminated with a cured film.
• Leaving a plug loose on a port that is under pressure. The symptom is a slow weep at the thread that increases with system pressure, because the cone has not been drawn onto the seat.

5. Applications and Industries

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

Concrete scenarios where a 4J adapter earns its place:

• Blanking unassigned ports on a manifold or a valve block. A manifold is often machined with more ports than the first build uses. Each spare female 74 degree seat port is closed with one plug, so the block can be put into service and the port brought into use later without replacing the block.
• Cap lines during transport, storage and flushing. A tube or hose assembly that leaves a workshop with open 74 degree seat ports can be closed for shipping, keeping dirt and moisture out of the circuit and protecting the seat from impact. The same plug is removed at the assembly station when the line is connected.
• Isolating a circuit for pressure testing. Where a branch has to be closed while another line is tested, a cone plug isolates that branch at the port with a joint of the same seal family as the rest of the circuit.
• Service and maintenance lock-off points. A port that is blanked with a plug can be opened for a gauge or a test point during maintenance without altering the pipework, because the plug seals on the same seat that the service connection will use.

The same part suits fluid power circuits, marine deck equipment, construction machinery and material handling systems, provided the mating port is a female 74 degree seat of the same dash size and the fluid suits the body material chosen, supplied as a steel hydraulic adapter in carbon steel or in stainless steel.

6. Replacement and Cross-Reference Guide

Replacement selection for this hydraulic plug adapter is organised by thread standard and sealing method, never by brand or catalogue number. A JIC male 74 degree cone plug is identified by three measurements, and nothing else is needed to find a matching part in the 4J table.

Measure these three things:

1. Measure the port thread: thread inside diameter and pitch in threads per inch. The dash sizes in this table run 7/16″X20 to 2.1/2″X12, and a matching plug must agree on both the diameter and the pitch.
2. Check the seat angle. A 74 degree seat is a wide cone seat, and it is not the same joint as a 37 degree flare. Check the port against SAE J514 before ordering, or compare the cone of the plug you are replacing with the cone of the new part.
3. Confirm that the port is an internal female seat and that the part required is a male cone plug. This JIC adapter is a male cone plug and it replaces a worn or damaged male 74 degree cone plug of the same dash size. It does not replace a female seat plug, which screws over a male cone, and it does not replace a flange plug or a pipe plug.

Once the three answers are known, choose the row whose E column matches the measured thread. Check A, L and S1 against the depth of the port and the wrench clearance around it before ordering.

Series that are commonly confused with 4J and are not interchangeable: the SAE J514 JIC 37 degree flare family, which seals on a conical flare face of a different angle; the SAE J1926-3 / ISO 11926-3 O-ring boss family, which seals with an O-ring on a straight-thread stud end plus a lock nut; the SAE J1453 ORFS family, which seals on a flat face against an elastomeric O-ring; the ISO 6162 flange plug families, which seal with an O-ring in a flange groove; and the NPT and BSPT tapered pipe thread families, which seal on the thread flanks and need a sealant.

7. Ordering, Packaging and Delivery

To order a 4J adapter from this series, give the series code plus the full part number, for example 4J-08, and confirm the following with the enquiry:

• Full part number, including any suffix shown on your drawing or packing list.
• Confirmation that the mating port is a female 74 degree seat of the matching dash size and thread.
• Body material: carbon steel, 304 stainless steel, 316 stainless steel or brass.
• Plating for carbon steel bodies: trivalent chromium zinc plating (Cr3+) or zinc-nickel plating.
• Whether a nut and sleeve are also required for a stud-end tube assembly on the same project, and whether the tube is metric or inch.
• Quantity and the required delivery date.

Parts are packed in labelled bags or boxes carrying the full part number, with cartons marked for size and quantity, and the cone face protected so that it arrives free of nicks, for distributor shelves or for direct-to-line OEM delivery. Sample orders and mixed-size trial orders are accepted before a production release, and custom sizes and drawing-based manufacture can be quoted for OEM programmes. Lead time is confirmed per order.

8. FAQ

What is the difference between JIC 37° flare and ORFS, and which should I use? A JIC 37° flare fitting seals metal-to-metal on a conical flare face and is specified by SAE J514 in the SAE 37° flared family. An ORFS fitting, specified by SAE J1453, seals on a flat face against an elastomeric O-ring held in a groove. Use the family that matches the port on your equipment. Neither one is a substitute for this plug, which has a 74 degree cone and closes a female 74 degree seat port only.

Can NPT and BSPT be interchanged? No. NPT is an American tapered pipe thread made to ANSI/ASME B1.20.1, and BSPT is a British tapered pipe thread made to ISO 7-1. They differ in thread form and pitch, so the same nominal size will often start by hand and then bind, and the joint will weep. Where a tapered pipe port has to be blanked, use a pipe plug from that family rather than forcing a 74 degree cone plug into it.

How do I identify the correct 4J adapter size? Measure the thread inside diameter and pitch of the port and match it to the E column of the table. Confirm that the port is a female 74 degree seat and not a 37 degree flare port.

What seal material should I select for my fluid and temperature? This plug has no elastomeric seal, because the 74 degree cone is a metal-to-metal joint, so the material decision here is the body and the plating. Carbon steel with trivalent chromium zinc plating suits general hydraulic service, and 304 or 316 stainless steel is selected for corrosive environments. Where an elastomer is used elsewhere in the same circuit, the published ranges are approximately -30°C to +100°C for NBR, -20°C to +200°C for FKM and -40°C to +120°C for EPDM.

How is the working pressure of this adapter determined? Working pressure is confirmed per order by HENGHUA engineering, based on the thread size, the body wall thickness, the sealing method and the material selected. Because a 7/16″X20 plug and a 2.1/2″X12 plug do not share one rating, no single figure is published for the whole series. The fluid and the length of time the port will stay blanked are also part of that review, since a plug is usually a long-term static closure.

What is the minimum order quantity and can I get samples? Sample orders and mixed-size trial orders are accepted for validation before a production release. Minimum order quantity depends on the size, the material and the plating selected, and it is confirmed with the quotation. Send the full part number and the quantity you need, and the order desk will quote the smallest practical release quantity for that configuration.

When would I use this plug instead of a hollow hex plug? Use the 4J plug where the port faces an open area and there is room for a wrench around it, or where the size required is larger than the hollow hex plug range. A hollow hex plug is better where the port is recessed or where adjacent fittings leave no room for an external wrench, because it is driven by an internal hex and sits at a lower height.

Send the full 4J adapter part number, the port thread and the quantity you need, and HENGHUA will confirm the drawing, the material and the lead time with the quotation.

Related series in the same family: the 9J adapter (plug) and the 1J adapter (straight). Browse the full Hydraulic Adapters range for the complete SAE J514 JIC, NPT, ORFS and ISO 6162 flange families.