5GB BSP Male O-Ring to BSP Female ISO 1179 Adapter — 5GB Adapter

1. What a 5GB Adapter Does

The 5GB adapter is a straight male-to-female conversion fitting. Connection 1 is a BSP male stud end that seals with an O-ring, and Connection 2 is a BSP female port built to ISO 1179 practice with a 60 degree cone seat. It converts a BSPP male port that is sealed by an O-ring into a female BSPP port, or the reverse, in one piece.

Core value: both ends have to match their mating port exactly. The male end must present the correct O-ring in the correct size against a flat port face, and the female end must receive a male stud end with the matching thread and cone. That is the precondition for eliminating leakage at the conversion point.

Sealing principle: the male end is sealed by an O-ring carried in its face, which is compressed against the flat face of the port when the adapter is tightened. The female end is sealed by the 60 degree cone seat defined in ISO 1179. Neither end seals on the thread flanks, because ISO 228-1 is a parallel thread.

2. 5GB Specifications

The blocks below present the two ends of the 5GB adapter in mirrored form, so a buyer can read off which port each end serves and which sealing method applies to each.

2.1 Connection 1 — BSP male, O-ring face seal (E end)

• Thread standard: ISO 228-1, pipe threads where pressure-tight joints are not made on the threads.
• Thread family: British Standard Pipe Parallel (BSPP / G).
• Gender: male.
• Size range: G1/4″x19 up to G1″x11.
• Sealing method: O-ring compressed against a flat port face.
• Mating port: BSPP port with a flat face that accepts an O-ring seal. Confirm the port face design against your drawing, because face depth and corner radius decide whether an O-ring or a bonded seal port is required.
• O-ring position: seated in the face of the male end, held concentric by the machined groove, so it is not displaced as the adapter is threaded in.

2.2 Connection 2 — BSP female, ISO 1179 60 degree cone seat (F end)

• Thread standard: ISO 228-1.
• Thread family: British Standard Pipe Parallel (BSPP / G).
• Gender: female.
• Size range: G1/4″x19 up to G1″x11.
• Sealing method: 60 degree cone seat.
• Mating port standard: ISO 1179 (BSPP port and stud end with 60 degree cone seat).
• Note: because the two ends are ordered by size code, the female end can be equal to or larger than the male end in the sizes listed.

2.3 Construction and Materials

The body is machined from bar stock on CNC lathes as one piece, so there is no brazed or welded joint in the pressure path. Body material options are carbon steel, 304 stainless steel, 316 stainless steel and brass. Carbon steel bodies are supplied with trivalent chromium zinc plating (Cr3+) or zinc-nickel plating, and stainless steel bodies are supplied bare.

The O-ring groove, the male thread and the flat seal face are turned in one setup, and the female cone seat is bored in the same setup family, so the O-ring lands square against the port face. The body carries a single hex across flats, given as S1 in the table.

The O-ring is the sealing element of the male end, so its material is selected for the fluid and temperature of the system: NBR, FKM or EPDM. The female end contains no elastomer, because it seals metal-to-metal on the cone. Thread gauges and dimensional checks are applied batch by batch before packing.

2.4 Pressure and Temperature

Working pressure for these sizes is confirmed per order by HENGHUA engineering, based on the sealing method, thread size and material selected. The O-ring face seal and the 60 degree cone seat do not carry the same pressure capability in every port design, so the confirmation is issued against the actual port and the actual O-ring chosen.

Carbon steel with zinc plating suits general hydraulic service, and 304 or 316 stainless steel are the options for corrosive and offshore service. The O-ring at the male end sets the temperature limit of that connection:

The female end of the adapter, which seals on a 60 degree cone, follows the body material and the fluid rather than an elastomer limit.

2.5 Part Number and Dimension Table

E is the male thread callout on Connection 1, F is the female thread callout on Connection 2 and the O-ring column gives the size code of the ring fitted to the male face. A is the male end length, L is the overall body length and S1 is the hex (spanner flat) size, all in millimetres and all taken from the drawing above.

O-ring size code by male thread, as listed above: O111 is fitted to G1/4″x19, O113 to G3/8″x19, O115 to G1/2″x14, O119 to G3/4″x14 and O217 to G1″x11.

3. How to Read a 5GB Adapter Part Number

The prefix 5GB identifies the series: straight body, BSP male O-ring end and BSP female ISO 1179 end. It is followed by one or two size codes that give the BSP size step of the male end and then of the female end.

A single code means both ends share one thread size, so 5GB-08 is G1/2″x14 male to G1/2″x14 female with an O115 ring. A double code means the ends differ, and the order matters: the first code is always the male E end and the second code is always the female F end.

Worked example from the table: 5GB-08-12 has a male E end of G1/2″x14 with an O115 O-ring, a female F end of G3/4″x14, an A dimension of 14 mm, an L dimension of 46 mm and a hex S1 of 36 mm. The reverse part number 5GB-12 does not exist as a mirror of that combination, so always state both sizes in the order E then F.

4. Installation and Fitment

Before assembly, check the O-ring on the male end and confirm it is the size listed for that thread, undamaged and free of grit. Fit a new O-ring where the existing one is cut, flattened or hardened, because an O-ring is a service item and not a permanent part of the adapter.

Thread the male end into the port by hand until the O-ring touches the port face, then tighten snug and apply the tightening angle specified for the size and material. The O-ring seals on the flat face, so the joint does not need high torque to be tight, and over-tightening only loads the threads and the hex. For the female end, follow the 60 degree cone procedure: clean the cone, thread in by hand until contact, then tighten to the specified angle.

Common fitment errors and their symptoms: an O-ring left out of the face leaks immediately at the port face, even when the adapter is tight; an O-ring of the wrong thickness holds the male end off the face and the joint weeps; a cut O-ring produced by a sharp port corner leaks at the first pressure cycle; and a BSPT male end fitted into the female end of this adapter leaks because a taper thread cannot register on a 60 degree cone.

5. Applications and Industries

Application tags for the 5GB adapter are hydraulic systems, water jetting, oil and gas equipment, industrial equipment, construction machinery, agriculture, marine and material handling. It is the part to use where a BSPP male port is O-ring sealed, or where the assembly must be dismantled and reassembled often without replacing a bonded seal each time.

Concrete scenarios: a mobile machine with O-ring sealed BSPP ports, where the adapter converts the port to a female connection for a hose assembly; a repair workshop that keeps the common sizes on the shelf so a damaged O-ring port can be re-terminated without re-machining the housing; a test bench where the male end is opened and closed repeatedly, because an O-ring reseals on its face after each refit far more reliably than a deformed bonded seal; and an OEM assembly line where the O-ring face seal gives a repeatable tightening result with less operator judgement.

6. Replacement and Cross-Reference Guide

Identify a replacement for a 5GB adapter by standard and sealing method, never by brand. This is a BSPP male to BSPP female part with ISO 228-1 parallel thread, an O-ring face seal at the male end and an ISO 1179 60 degree cone seat in the female end.

Measure these three things before ordering: first, the male thread outside diameter and threads per inch, to confirm an ISO 228-1 G thread at 19, 14 or 11 threads per inch in the sizes offered; second, the port face at the male end, checking that it is a flat face that accepts an O-ring and measuring the face depth; third, the female end thread size and the seat inside it, confirming a 60 degree cone.

7. Ordering, Packaging and Delivery

To order a 5GB adapter, give the series code with the full part number, both thread sizes in the order E then F, the body material, the plating, the O-ring material and the quantity. For example: series 5GB, part number 5GB-08-12, male E end G1/2″x14 with O115 O-ring in NBR, female F end G3/4″x14, carbon steel with trivalent chromium zinc plating, 500 pieces.

State the O-ring material even where NBR is assumed, because the fluid and temperature of the system decide the correct compound and the O-ring is fitted to the order. Packaging is arranged for distributor shelves and for direct-to-line delivery, with thread protection in transit and labels carrying the part number and both thread sizes. Samples are available for validation, and lead time is confirmed per order once thread sizes, material and quantity are fixed.

8. FAQ

Q1. What is the difference between BSPP and BSPT, and can they be interchanged? BSPP is the parallel pipe thread defined in ISO 228-1, which is the thread used at both ends of this series. BSPT is the taper thread defined in ISO 7-1, which seals on the thread flanks and needs a sealant. They are not interchangeable, and a taper male end fitted into the female end of this adapter cannot reach the cone seat, so the joint leaks and both threads are damaged.

Q2. What is the difference between a 60 degree cone seat and a bonded seal, and which should I choose? A 60 degree cone seat is a metal-to-metal seal between the cone on a male stud end and the cone inside this adapter female end, and it uses no elastomer. A bonded seal is a metal washer with a bonded elastomer ring that seals between two flat faces. This series uses an O-ring on the male face instead, and a 60 degree cone seat in the female end, so choose the mating components to match those two sealing methods.

Q3. How do I identify the correct 5GB size? Read the thread callout of the port the male end enters, then the thread of the male stud end the female end receives. The first size code is the male end and the second is the female end, so 5GB-08-12 is a G1/2″x14 male end into a G3/4″x14 female end. Where both connections are the same size, the part number carries one code, for example 5GB-08 with an O115 O-ring.

Q4. What seal material should I select for my fluid and temperature? The O-ring on the male face is the elastomer to select: NBR covers approximately -30°C to +100°C, FKM approximately -20°C to +200°C, and EPDM approximately -40°C to +120°C. The female end has no elastomer and follows the body material and the fluid. Body options are carbon steel with trivalent chromium zinc plating, 304 or 316 stainless steel, and brass.

Q5. How is the working pressure of this adapter determined? Working pressure for these sizes is confirmed per order by HENGHUA engineering, based on the sealing method, thread size and material selected. The O-ring face seal at the male end and the 60 degree cone seat at the female end do not carry the same capability in every port design, so the confirmation is issued against the actual port, the actual O-ring compound and the expected system pressure that you send with the inquiry.

Q6. What is the difference between this O-ring male end and the double use male end on other BSPP adapters? The double use male end carries a 60 degree cone that seats metal-to-metal, and can also seal with a bonded seal on its flat shoulder. The male end on this series has no cone nose and seals with an O-ring in its face against a flat port face. Choose the O-ring version where the port is designed for an O-ring face seal, and the double use version where the port has a 60 degree cone or takes a bonded seal.

Q7. Can I change the O-ring size or material myself? Fit the O-ring size listed for the male thread, because the groove and the face are machined to that size and a ring of the wrong thickness will hold the adapter off the port face. The material can be selected within the NBR, FKM and EPDM options to suit the fluid; state the choice when ordering so the correct compound is fitted and supplied as a spare with the parts.

Q8. What is the minimum order quantity and can I get samples? Minimum order quantity depends on the size, the material, the plating and the O-ring compound selected, and is confirmed with the quotation. Samples are available for validation, and for a part number such as 5GB-08-12 a sample is the normal way to confirm that the male face seal closes correctly on the actual port before a production order. Lead time is confirmed per order.

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