{"id":5289,"date":"2026-09-19T03:15:09","date_gmt":"2026-09-19T03:15:09","guid":{"rendered":"https:\/\/www.henghuahose.com\/?post_type=product&p=5289"},"modified":"2026-09-19T03:15:11","modified_gmt":"2026-09-19T03:15:11","slug":"sae-o-ring-boss-l-series-iso-11926-3-sae-female-iso-11926-1-adapter-5o","status":"publish","type":"product","link":"https:\/\/www.henghuahose.com\/de\/product\/sae-o-ring-boss-l-series-iso-11926-3-sae-female-iso-11926-1-adapter-5o\/","title":{"rendered":"5O SAE O-Ring Boss L-Series ISO 11926-3 to SAE Female ISO 11926-1 Adapter – 5O Adapter"},"content":{"rendered":"
The 5O adapter is a two-port SAE adapter that joins a SAE O-ring boss L series stud end to a tapped SAE straight thread female port. The stud end is machined to ISO 11926-3 and seals on an O-ring; the tapped end is machined to ISO 11926-1 and seals on the O-ring of the male stud end screwed into it. The printed table lists 26 part numbers from size code 04 to size code 32, so the series covers equal-ended and reducing combinations.<\/p>\r\n\r\n\r\n\r\n
Core Advantages<\/h2>\r\n\r\n\r\n\r\n
\r\n
Joins a SAE O-ring boss stud end (ISO 11926-3) to a SAE straight thread female port (ISO 11926-1) in one body.<\/li>\r\n\r\n\r\n\r\n
Each end is machined to its own published standard, so both joints match their mating parts.<\/li>\r\n\r\n\r\n\r\n
26 printed part numbers from size code 04 to size code 32, including a full set of reducing combinations.<\/li>\r\n\r\n\r\n\r\n
Seals on elastomeric O-rings, so the thread only clamps and no thread sealant is used.<\/li>\r\n\r\n\r\n\r\n
Carbon steel with trivalent chromium zinc plating, or 304 \/ 316 stainless steel for corrosive service.<\/li>\r\n\r\n\r\n\r\n
O-ring material options of NBR, FKM and EPDM to match your fluid and temperature.<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
1. What a 5O Fitting Does<\/h2>\r\n\r\n\r\n\r\n
A 5O adapter is a two-port hydraulic item, not a blanking plug. The stud end screws into a SAE O-ring boss port and seals there on an O-ring; the tapped end receives the male stud end of a hose fitting, a tube fitting or another adapter and seals on that part’s O-ring. Fluid passes straight through the body and nothing is closed.<\/p>\r\n\r\n\r\n\r\n
The problem it solves is a mismatch of SAE port sizes in one circuit: a manifold or a cylinder may carry a SAE straight thread boss of one size while the hose assembly is built with another. The O-ring boss adapter bridges the two and keeps the O-ring principle at both ends.<\/p>\r\n\r\n\r\n\r\n
The sealing principle is the one shared by every straight-thread O-ring joint: an elastomeric O-ring is compressed in a machined recess on the port face, and the parallel thread only clamps the parts together. At the stud end the O-ring sits in the groove on the stud; at the tapped end the body carries the recess for the O-ring of the mating male stud end.<\/p>\r\n\r\n\r\n\r\n
The core value of the 5O adapter is an exact match at both ends: the stud end must match the port, and the tapped end must match the stud end fitted into it, including the O-ring recess. When an O-ring boss adapter matches at both ends the joint is durable; when either end does not, no amount of torque will stop the leak.<\/p>\r\n\r\n\r\n\r\n
2. 5O Specifications<\/h2>\r\n\r\n\r\n\r\n
2.1 Connection 1 – SAE O-ring boss L series stud end (ISO 11926-3)<\/h3>\r\n\r\n\r\n\r\n
Connection 1 is a male stud end with an inch UNF straight thread and an O-ring groove behind the nose. It is the light duty L series, and the printed standard is ISO 11926-3, the SAE straight thread O-ring boss stud end, light duty series, known in SAE numbering as SAE J1926-3. Because both ends follow that family, this is an ISO 11926 adapter in the strict sense.<\/p>\r\n\r\n\r\n\r\n
\r\n
Thread standard and family: SAE inch UNF straight thread, O-ring boss stud end, L series, to ISO 11926-3 (SAE J1926-3).<\/li>\r\n\r\n\r\n\r\n
Thread size range printed at this end: from 7\/16\"X20<\/code> at size code 04 to 2.1\/2\"X12<\/code> at size code 32.<\/li>\r\n\r\n\r\n\r\n
Gender: male.<\/li>\r\n\r\n\r\n\r\n
Sealing method: an elastomeric O-ring carried on the stud and compressed in the recess of the mating port; the thread clamps and does not seal.<\/li>\r\n\r\n\r\n\r\n
Mating port: a SAE straight thread O-ring boss port to ISO 11926-1 (SAE J1926-1).<\/li>\r\n\r\n\r\n\r\n
O-ring: one O-ring is required at this end only; the printed O-ring column belongs to this end and to no other.<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
2.2 Connection 2 – SAE female straight thread port (ISO 11926-1)<\/h3>\r\n\r\n\r\n\r\n
Connection 2 is a tapped female port machined into the body. It uses the same SAE inch UNF straight thread family, but its role is reversed: this end is the port, not the stud end, and the printed standard is SAE female ISO 11926-1. The body therefore acts as a female adapter at this end and as a straight thread adapter overall.<\/p>\r\n\r\n\r\n\r\n
\r\n
Thread standard and family: SAE inch UNF straight thread, O-ring boss port, to ISO 11926-1 (SAE J1926-1).<\/li>\r\n\r\n\r\n\r\n
Thread size range printed at this end: from 7\/16\"X20<\/code> to 1.7\/8\"X12<\/code>.<\/li>\r\n\r\n\r\n\r\n
Gender: female.<\/li>\r\n\r\n\r\n\r\n
Sealing method: the joint seals on the O-ring of the mating male stud end, compressed in the recess machined at the mouth of this port; the thread clamps and does not seal.<\/li>\r\n\r\n\r\n\r\n
Mating part: a SAE O-ring boss male stud end or hose end with the matching size and recess.<\/li>\r\n\r\n\r\n\r\n
O-ring: no O-ring is fitted at this end; the printed table has one O-ring column only, and it belongs to the stud end.<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
The two blocks are symmetrical: the stud end carries an O-ring and looks for a recess, while the tapped end is a female adapter port that looks for the O-ring of the mating part. That is why this O-ring boss adapter needs only one O-ring column.<\/p>\r\n\r\n\r\n\r\n
2.3 Construction and Materials<\/h3>\r\n\r\n\r\n\r\n
The body is machined from bar stock on CNC lathes, with the stud end thread, the O-ring groove, the tapped port thread, the port recess and the hex held concentric to one axis. Concentricity matters more here than on a single-ended item, because there are two sealing faces to align.<\/p>\r\n\r\n\r\n\r\n
\r\n
One-piece machined body with no brazed or welded joint, so there is no secondary joint to leak.<\/li>\r\n\r\n\r\n\r\n
Stud end groove produced to ISO 11926-3 so the O-ring seats correctly in the mating ISO 11926-1 recess.<\/li>\r\n\r\n\r\n\r\n
Tapped end thread and recess produced to ISO 11926-1, so a standard SAE O-ring boss stud end seals in it.<\/li>\r\n\r\n\r\n\r\n
External body hex, printed as S1 for every size, and a straight through bore with no cross drilling.<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
Material and finish options: carbon steel with trivalent chromium zinc plating (Cr3+), carbon steel with zinc-nickel plating, 304 or 316 stainless steel for corrosive service, and brass on the smaller sizes. The O-ring at the stud end is available in NBR, FKM and EPDM, fitted to the stud or supplied separately.<\/p>\r\n\r\n\r\n\r\n
2.4 Pressure and Temperature<\/h3>\r\n\r\n\r\n\r\n
Working pressure for these sizes is confirmed per order by HENGHUA engineering, based on the thread size, sealing method and material selected. The printed chart for this series carries no pressure column, so no per-size rating is quoted here. On a two-port part, the smaller of the two connections governs the assembly.<\/p>\r\n\r\n\r\n\r\n
Temperature is governed by the O-ring material, the only soft part in the joint. The material facts are NBR approximately -30\u00b0C to +100\u00b0C, FKM approximately -20\u00b0C to +200\u00b0C and EPDM approximately -40\u00b0C to +120\u00b0C. NBR suits general hydraulic oil and water service, FKM suits high temperature and aggressive fluids, and EPDM suits water, steam and many brake and glycol fluids.<\/p>\r\n\r\n\r\n\r\n
2.5 Part Number and Dimension Table<\/h3>\r\n\r\n\r\n\r\n
Dimensions A, L and S1 are in millimetres. Thread values are printed in standard inch notation.<\/p>\r\n\r\n\r\n\r\n
What each column means<\/strong><\/p>\r\n\r\n\r\n\r\n
\r\n
PART NO.<\/strong> – the series code 5O, then the size code of the stud end, then the size code of the tapped end when the two differ. A number with a single code, such as 5O-10, is equal-ended.<\/li>\r\n\r\n\r\n\r\n
E<\/strong> – the thread of the stud end, the O-ring boss end that screws into the port.<\/li>\r\n\r\n\r\n\r\n
F<\/strong> – the thread of the tapped female port in the body, which is the thread of the male stud end fitted into the adapter.<\/li>\r\n\r\n\r\n\r\n
O-RING E<\/strong> – the O-ring required at the E end only, printed as O plus the inside diameter code, for example O908. There is no O-ring column for the F end.<\/li>\r\n\r\n\r\n\r\n
A<\/strong> – the length from the stud end face to the hex face, in millimetres.<\/li>\r\n\r\n\r\n\r\n
L<\/strong> – the overall length of the body, in millimetres.<\/li>\r\n\r\n\r\n\r\n
S1<\/strong> – the width across flats of the body hex, in millimetres.<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
Thread size and dash chart, stud end (E)<\/strong><\/p>\r\n\r\n\r\n\r\n
\r\n
\r\n\r\n
\r\n
Size code<\/th>\r\n
E thread<\/th>\r\n
O-ring<\/th>\r\n
Printed part numbers with this E end<\/th>\r\n<\/tr>\r\n<\/thead>\r\n
Tapped end sizes printed in the series: 7\/16\"X20<\/code>, 9\/16\"X18<\/code>, 3\/4\"X16<\/code>, 7\/8\"X14<\/code>, 1.1\/16\"X12<\/code>, 1.3\/16\"X12<\/code>, 1.5\/16\"X12<\/code>, 1.5\/8\"X12<\/code>, 1.7\/8\"X12<\/code>. Ten stud end sizes and nine tapped end sizes combine into 26 printed part numbers, so a buyer who quotes only one size code has not yet specified the part.<\/p>\r\n\r\n\r\n\r\n
3. How to Read a 5O Adapter Part Number<\/h2>\r\n\r\n\r\n\r\n
A part number in this series reads left to right as series, stud end, tapped end.<\/p>\r\n\r\n\r\n\r\n
\r\n
Prefix 5O<\/code><\/strong> – the series code for the SAE O-ring boss L series stud end to SAE female port adapter.<\/li>\r\n\r\n\r\n\r\n
First size code<\/strong> – the size of the E end, the stud end that screws into the port and carries the O-ring.<\/li>\r\n\r\n\r\n\r\n
Second size code<\/strong> – the size of the F end, the tapped port in the body; it is printed only when it differs from the first size code.<\/li>\r\n\r\n\r\n\r\n
No suffix<\/strong> – body material, plating and O-ring material are specified separately on the order.<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
Worked example, equal-ended: 5O-10<\/strong>. The stud end E is 7\/8\"X14<\/code> and the tapped end F is also 7\/8\"X14<\/code>, so the adapter joins two ports of the same SAE size. It uses O-ring O910, with A at 12.7 mm, L at 38 mm and S1 at 30 mm.<\/p>\r\n\r\n\r\n\r\n
Worked example, reducing: 5O-12-08<\/strong>. The stud end E is 1.1\/16\"X12<\/code> and the tapped end F is 3\/4\"X16<\/code>, so the adapter screws into a size 12 SAE O-ring boss port and offers a smaller size 08 port to the hose end. It uses O-ring O912, with A at 15.09 mm, L at 26 mm and S1 at 32 mm.<\/p>\r\n\r\n\r\n\r\n
Reading order matters. Reversing the two size codes specifies a different part: 5O-12-08 is not the same as 5O-08-12, because the O-ring, the hex and the overall length all change with the end that carries the seal.<\/p>\r\n\r\n\r\n\r\n
4. Installation and Fitment<\/h2>\r\n\r\n\r\n\r\n
The governing rule on the 5O adapter is that the O-ring is the seal and the thread is only the clamp. Never omit the O-ring, and never seal the thread with tape or a liquid sealant, because a straight inch UNF thread with an O-ring has no sealing function in the thread itself.<\/p>\r\n\r\n\r\n\r\n
Both ends follow that rule in mirror image. At the stud end, the O-ring is fitted to the stud and compressed into the recess of the port as the thread is tightened. At the tapped end, the O-ring belongs to the mating male stud end. If the tapped end leaks, the fault is normally the O-ring of that mating part rather than the adapter.<\/p>\r\n\r\n\r\n\r\n
Assembly steps:<\/p>\r\n\r\n\r\n\r\n
\r\n
Confirm both ends before assembly: the stud end thread must match the port, and the tapped end thread must match the stud end fitted into it.<\/li>\r\n\r\n\r\n\r\n
Inspect the O-ring and both recesses, replacing any O-ring that is cut, flattened, swollen or hardened and checking for nicks and embedded debris.<\/li>\r\n\r\n\r\n\r\n
Lubricate the O-ring sparingly with a compatible fluid and seat it in its groove without twisting it.<\/li>\r\n\r\n\r\n\r\n
Start both threads by hand, turning the adapter in until the stud end face meets the port face and keeping the body square.<\/li>\r\n\r\n\r\n\r\n
Tighten in words, not by guesswork. Bring the faces into contact, apply a controlled final torque with a socket on the hex, and hold the adapter steady while tightening the second joint.<\/li>\r\n\r\n\r\n\r\n
Re-check both joints after the first heat cycle, then examine them under working pressure.<\/li>\r\n<\/ol>\r\n\r\n\r\n\r\n
Common fitment errors and their symptoms:<\/p>\r\n\r\n\r\n\r\n
\r\n
Fitting a heavy duty stud end into a light duty port, or the reverse. Symptom: the stud end bottoms on the wrong face and the joint weeps from first pressurisation.<\/li>\r\n\r\n\r\n\r\n
Omitting the O-ring and relying on thread sealant. Symptom: a leak along the thread that returns as soon as the sealant softens.<\/li>\r\n\r\n\r\n\r\n
Reversing the two size codes when ordering. Symptom: the stud end fits but the tapped end does not accept the hose end.<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
5. Applications and Industries<\/h2>\r\n\r\n\r\n\r\n
Application tags for this series: hydraulic systems, oil and gas, industrial equipment, construction machinery, agriculture, marine, material handling, water jetting. Because the 5O adapter joins two SAE straight thread ports of different sizes, it appears wherever a SAE circuit is assembled from mixed-size components.<\/p>\r\n\r\n\r\n\r\n
Manifold and valve block adaptation.<\/strong> A valve block may be machined with SAE O-ring boss ports sized for its internal passages, while the hose assemblies are built with another stud end size. The adapter screws into the block and presents the port size the hose needs, so neither the block nor the hose is redesigned.<\/p>\r\n\r\n\r\n\r\n
Cylinder port matching.<\/strong> Cylinder ports and the hose ends specified for them do not always agree, especially on older equipment. A reducing SAE adapter keeps the joint inside the SAE O-ring family and avoids importing another thread family into the same circuit.<\/p>\r\n\r\n\r\n\r\n
Repair and field service.<\/strong> When a hose end or a port is damaged and only another size in the same SAE family is available, a straight thread adapter restores the machine to service without waiting for the original part, and a small stock of common reducing combinations shortens downtime.<\/p>\r\n\r\n\r\n\r\n
These adapters suit mobile and industrial hydraulics, oilfield equipment, construction machinery, agriculture and marine deck machinery.<\/p>\r\n\r\n\r\n\r\n
6. Replacement and Cross-Reference Guide for the 5O Adapter<\/h2>\r\n\r\n\r\n\r\n
This guide is organised by standard and sealing method, not by brand, because a part of this type is defined by its two thread ends and its O-ring.<\/p>\r\n\r\n\r\n\r\n
Step one: identify the thread form.<\/strong> Both ends are SAE inch UNF straight thread. Measure the outside diameter of the stud end thread and count the threads per inch, do the same inside the tapped end, and match both to the printed table. Metric threads of similar diameter are not interchangeable with inch UNF.<\/p>\r\n\r\n\r\n\r\n
Step two: identify the sealing method.<\/strong> This series seals on elastomeric O-rings at both ends, so neither end should be matched to a taper thread or to a port without an O-ring recess. A 60\u00b0 metal cone seat and a bonded seal flat face belong to other families and need other parts. If a port has no machined recess for an O-ring, a SAE adapter of this type is not the correct choice.<\/p>\r\n\r\n\r\n\r\n
Step three: identify the standard of each end.<\/strong> The stud end is an L series item to ISO 11926-3, equivalent to SAE J1926-3, and the tapped end is a port to ISO 11926-1, equivalent to SAE J1926-1, so the body is an ISO 11926 adapter at both ends. The light duty L series and the heavy duty S series are separate families and are not interchangeable even when the thread is the same; this printed range is the L series only.<\/p>\r\n\r\n\r\n\r\n
The three things to measure before you order<\/strong><\/p>\r\n\r\n\r\n\r\n\r\n
Stud end thread outside diameter and threads per inch.<\/li>\r\n\r\n\r\n\r\n
Tapped end thread inside diameter and threads per inch.<\/li>\r\n\r\n\r\n\r\n
O-ring recess diameter and depth at each port, or the port designation from the machine manual.<\/li>\r\n<\/ol>\r\n\r\n\r\n\r\n
One practical check catches most ordering errors on this series: count the two size codes against the drawing before releasing the order. A reducing adapter is only correct when the first code matches the port and the second code matches the hose end, in that order.<\/p>\r\n\r\n\r\n\r\n
7. Ordering, Packaging and Delivery<\/h2>\r\n\r\n\r\n\r\n
To place an order, give HENGHUA the series code plus the full part number plus the options:<\/p>\r\n\r\n\r\n\r\n
\r\n
Series and part number, for example 5O-12-08<\/code>.<\/li>\r\n\r\n\r\n\r\n
Body material: carbon steel, 304 stainless steel, 316 stainless steel or brass.<\/li>\r\n\r\n\r\n\r\n
Plating, for carbon steel: trivalent chromium zinc plating (Cr3+) or zinc-nickel plating.<\/li>\r\n\r\n\r\n\r\n
O-ring material: NBR, FKM or EPDM, and whether the O-ring should be supplied fitted or separately.<\/li>\r\n\r\n\r\n\r\n
Quantity, and whether the order is a trial batch or a production release.<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n
Because the part number already carries both ends, there is no need to describe the part in words on the order. Quote the printed number and add the material, plating and O-ring options. This ISO 11926 adapter is a straight thread adapter and a female adapter in one body, so the two thread designations on the order are enough for a supplier to identify it.<\/p>\r\n\r\n\r\n\r\n
Packaging follows normal export practice. Parts are counted, bagged by size and boxed, with the part number, the two thread sizes, the material and the O-ring material shown on each bag label and on the outer carton. Mixed-size orders are separated by size inside the carton.<\/p>\r\n\r\n\r\n\r\n
Samples for validation are available on request, and lead time is confirmed per order. On a reducing range this wide, ordering a sample of the exact combination before releasing a production batch is sensible, because a two-end part cannot be reworked after machining.<\/p>\r\n\r\n\r\n\r\n
8. FAQ<\/h2>\r\n\r\n\r\n\r\n
What is the difference between a straight-thread O-ring seal and a tapered pipe thread?<\/strong><\/p>\r\n\r\n\r\n\r\n
A straight-thread O-ring joint seals on an elastomeric O-ring compressed in a machined recess on the port face, and the parallel thread only clamps the parts together. A tapered pipe thread has no recess and seals by interference between the thread flanks, so it needs a sealant. This series uses the straight-thread O-ring principle at both ends and needs no thread sealant anywhere.<\/p>\r\n\r\n\r\n\r\n
Can BSP and NPT be interchanged?<\/strong><\/p>\r\n\r\n\r\n\r\n
No. BSP threads have a 55\u00b0 thread angle and NPT threads have a 60\u00b0 thread angle, and their pitches and diameters differ even at the same nominal size, so a BSP male will not seal in an NPT port. This series is inch UNF SAE straight thread at both ends and belongs to neither family. Order by the printed thread designation rather than by an approximate diameter.<\/p>\r\n\r\n\r\n\r\n
How do I identify the correct 5O adapter size?<\/strong><\/p>\r\n\r\n\r\n\r\n
Read the part number as stud end first and tapped end second, then match both threads to the table. 5O-10<\/code> is equal-ended at 7\/8\"X14<\/code>, while 5O-12-08<\/code> has a 1.1\/16\"X12<\/code> stud end and a 3\/4\"X16<\/code> tapped end. Measure both threads and compare them with the printed values.<\/p>\r\n\r\n\r\n\r\n
What seal material should I select for my fluid and temperature?<\/strong><\/p>\r\n\r\n\r\n\r\n
Select the O-ring material for the stud end, since that is the only O-ring on the part. Choose NBR for general hydraulic oil and water service at moderate temperature, FKM for high temperature and aggressive fluids, and EPDM for water, steam and many brake and glycol fluids. The material facts are NBR approximately -30\u00b0C to +100\u00b0C, FKM approximately -20\u00b0C to +200\u00b0C and EPDM approximately -40\u00b0C to +120\u00b0C.<\/p>\r\n\r\n\r\n\r\n
How is the working pressure of this fitting determined?<\/strong><\/p>\r\n\r\n\r\n\r\n
The printed chart for this series has no pressure column, so no per-size rating is quoted here. Working pressure for these sizes is confirmed per order by HENGHUA engineering, based on the thread size, sealing method and material selected. On this adapter the smaller of the two connections governs the assembly, together with the body material and the thread size.<\/p>\r\n\r\n\r\n\r\n
What is the minimum order quantity and can I get samples?<\/strong><\/p>\r\n\r\n\r\n\r\n
Minimum order quantity is confirmed per order because it depends on the series, the size combination and the material. Samples for validation are available on request. Send the part number, the material and the quantity you want to evaluate, and HENGHUA will confirm the sample arrangement and the lead time in the quotation.<\/p>\r\n\r\n\r\n\r\n
Does the tapped end of the adapter need its own O-ring?<\/strong><\/p>\r\n\r\n\r\n\r\n
No. Only the stud end carries an O-ring, and it is listed in the single O-ring column of the printed table. The tapped end is a port machined to ISO 11926-1, and it seals on the O-ring of the male stud end screwed into it.<\/p>\r\n\r\n\r\n\r\n
How do I choose between an equal-ended and a reducing 5O?<\/strong><\/p>\r\n\r\n\r\n\r\n
Match the first size code to the port the adapter screws into and the second size code to the hose end fitted into it. If the two are equal, the number is printed with one code, such as 5O-16<\/code>. If they differ, the number carries both codes, such as 5O-16-12<\/code>. Reversing the codes specifies a different part with a different O-ring, hex and overall length.<\/p>\r\n\r\n\r\n\r\n
This series is one body with two SAE straight thread ends: a light duty O-ring boss stud end to ISO 11926-3 and a tapped female port to ISO 11926-1, with 26 printed part numbers from size 04 to size 32. Send HENGHUA your two thread sizes, the port designation, your fluid, your body material and the quantity, and HENGHUA will confirm the exact part number, the O-ring material and the plating so that both ends of the 5O adapter you receive match the two ends you are joining.<\/p>\r\n\r\n\r\n\r\n
![\"SAE](\"https:\/\/www.henghuahose.com\/wp-content\/uploads\/2026\/09\/sae-o-ring-boss-l-series-iso-11926-3-sae-female-iso-11926-1-adapter-5o-dimensions.png\")
<\/figure>\r\n\r\n\r\n\r\n\r\n