1BT-SP Adapter — Straight, BSP Male Double Use 60° Seat or Bonded Seal to BSPT Male

1. What a 1BT-SP Adapter Does

The 1BT-SP adapter is a straight hydraulic conversion adapter that joins a BSPP port to a BSPT port. Connection 1 is a BSPP male stud end to ISO 228-1 with a double-use sealing design: it seals on a 60° cone seat against an ISO 1179 cone seat port, or on a bonded seal against a flat face port. Connection 2 is a BSPT male taper thread to ISO 7-1. Because the body is straight, the adapter adds length to the run but does not change its direction.

Both connection ends must match their mating port exactly, because that is the precondition for eliminating leakage at the conversion point. A 1BT-SP adapter does not try to make a parallel thread behave like a taper thread; it carries one correctly machined end for each port, so neither port has to be modified and no thread has to be forced.

The double-use end is what separates this series from a single-purpose elbow. The BSPP end has a machined 60° cone, so it can seal directly against a mating cone; when the port face is flat instead, the same end is used with a bonded seal (Dowty-type washer). The BSPT end is a taper thread that seals on the thread flanks and requires a sealant. BSPP and BSPT share a 55° thread angle but differ in pitch and taper, so the two ends can never be interchanged.

2. 1BT-SP Specifications

2.1 Connection 1 — BSPP (G) male stud end, double use for 60° seat or bonded seal

• Thread standard: ISO 228-1 parallel pipe thread (BSPP, G thread).
• Mating port standard: ISO 1179, ports and stud ends with ISO 228-1 threads, covering the 60° cone seat and bonded seal configurations.
• Gender: male stud end.
• Available thread sizes on Connection 1: G1/8″x28 to G3″x11, covering the Thread E column in the table in section 2.5.
• Sealing method, option 1: 60° cone seat against the mating cone. No separate sealing part is needed.
• Sealing method, option 2: bonded seal (Dowty-type washer) against a flat face. This is the arrangement used when the port has no cone.
• Double-use rule: the same stud end covers both port types, which reduces the number of part numbers a distributor or a maintenance store has to hold. At the point of assembly the two options are still distinct, and the correct one is set by the port, not by preference.
• Seat rule: the BSPP threads are not the sealing element in either option. They position the stud end while the cone or the bonded seal produces the pressure-tight joint.
• Hex: a hex (S1) on the body gives a spanner face, so tightening load is carried by the adapter rather than by the connected pipework.

2.2 Connection 2 — BSPT male taper thread

• Thread standard: ISO 7-1 pipe threads where pressure-tight joints are made on the threads (BSPT, R thread).
• Gender: male taper thread.
• Available thread sizes on Connection 2: R1/8″x28 to R3″x11, covering the Thread F column in the table in section 2.5.
• Sealing method: the taper thread seals on the thread flanks, so a thread sealant suited to the fluid and the system is applied before assembly.
• Reuse rule: inspect a previously fitted taper end for flattened or galled threads before reuse, because the joint depends on flank contact.
• Cross-standard note: a BSPT adapter seals on the flanks while a BSPP adapter seals on the seat, so the two are never interchangeable. Never force a BSPP parallel stud end into a BSPT port, and never screw a BSPT taper end into a BSPP parallel port.

2.3 Construction and Materials

The body is machined from bar stock on CNC lathes. The 60° seat and the taper thread are produced as separate operations, and thread gauges and dimensional checks are applied batch by batch before packing.

• Body material options: carbon steel, 304 stainless steel, 316 stainless steel, with brass available as an option.
• Plating options for carbon steel: trivalent chromium zinc plating (Cr3+) or zinc-nickel plating. Stainless steel bodies are supplied without plating.
• Seal material options: NBR, FKM (Viton-type) and EPDM bonded seals or O-rings, matched to the fluid and the temperature of the application. A bonded seal adapter is only as good as the washer fitted, so the seal material is specified with the part number rather than chosen at the bench.
• Critical surfaces: the 60° cone seat and the taper thread are treated as sealing surfaces during machining, handling and packing.
• Hex feature: one hex across flats (S1) on the body, sized per thread combination as listed in the table.

2.4 Pressure and Temperature

Pressure is governed by the thread size, the wall thickness of the body, the sealing method and the material selected, so it is confirmed per order rather than published as a single figure for the range. Working pressure for these sizes is confirmed per order by HENGHUA engineering, based on the sealing method, thread size and material selected.

Temperature capability follows the seal material, which is a material fact rather than a rating of the adapter body:

Carbon steel with zinc plating covers general hydraulic service. Choose 304 or 316 stainless steel for corrosive environments, offshore duty and wash-down areas where the BSPT thread is exposed.

2.5 Part Number and Dimension Table

Column key: E is the BSPP (G) male stud end on Connection 1. F is the BSPT (R) male taper end on Connection 2. A and B are the two end lengths in the order shown on the specification drawing, L is the overall length and S1 is the hex across flats, in millimetres.

Note: the two largest rows sit on the bottom edge of the specification image. Their thread sizes follow the series pattern and the values are reproduced as printed, but confirm 1BT-40SP and 1BT-48SP with HENGHUA before ordering those sizes.

3. How to Read a 1BT-SP Adapter Part Number

Every part number in this series follows the same pattern, so the table can be read without a separate catalogue.

• Prefix 1BT-SP: the family code. 1 marks the male-to-male conversion group, B marks the BSPP end with a 60° seat, T marks the BSPT male taper end, and SP is the suffix carried by every part number in this series as listed in the specification. There is no angle digit in this prefix because the body is straight.
• First size code after the dash: the Thread E size on the BSPP end.
• Optional second size code: the Thread F size on the BSPT end. When only one size code is present, E and F are the same nominal size, as in 1BT-08SP.
• Two-digit codes repeat the numerator of the thread size, which can be verified from any row: 02 = 1/8″, 04 = 1/4″, 06 = 3/8″, 08 = 1/2″, 10 = 5/8″, 12 = 3/4″, 16 = 1″, 20 = 1.1/4″, 24 = 1.1/2″, 32 = 2″, 40 = 2.1/2″, 48 = 3″.
• The 10 code appears only where a G5/8″ BSPP end is combined with a smaller BSPT end, as in 1BT-10-08SP and 1BT-10-12SP.

Worked example, row 1BT-12-16SP: 1BT-SP is the straight BSPP-to-BSPT male family, 12 is the Thread E code for G3/4″x14 on the BSPP end, and 16 is the Thread F code for R1″x11 on the BSPT end. The row then gives A = 18.5 mm, B = 25.5 mm, L = 53.5 mm and S1 = 36 mm. The same size pair in an elbow body would carry 9 or 4 in the prefix instead.

4. Installation and Fitment

• Inspect before assembly. Check that the 60° cone seat is free of burrs, scores and swarf, and that the BSPT taper thread is clean and undamaged. A scored seat cannot be recovered by additional tightening.
• Decide the sealing arrangement before you start, from the port and not from habit. A cone seat port needs the 60° seat only; a flat face port needs a bonded seal between the adapter shoulder and the port face.
• Apply sealant only where the sealing method requires it. The BSPT taper end seals on the thread flanks and needs a sealant suited to the fluid. The BSPP end seals on the seat or on the bonded seal and needs no thread sealant.
• Renew the bonded seal at every assembly. Bonded seals are single-use parts, and a re-used washer is a common cause of a joint that weeps at the face while the threads remain undamaged.
• Align before tightening. Start both ends by hand and confirm the threads run in freely, then tighten to snug contact and apply the additional tightening angle specified for the joint. No tightening angle value appears in the series specification, so work to the value in your assembly instruction or confirm it with HENGHUA engineering.
• Use the hex. Tighten on the S1 hex with a spanner that fits, so the load passes through the body rather than through the taper thread.
• Contamination control. Keep the adapter capped until fitting, work with clean tools and flush the circuit afterwards where swarf ingress is possible.

Common fitment errors and their symptoms:

5. Applications and Industries

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

Concrete scenarios where this cross standard adapter is used:

1. Cross-standard equipment integration. A machine built to a mixed specification presents a BSPT taper port on a valve while the circuit uses BSPP adapters and ISO 1179 practice. This series converts the taper port to a BSPP 60° seat face in line with the existing run, so hose assemblies and torque records stay valid.
2. Distributor stock rationalisation. Because the BSPP end covers both a cone seat port and a flat face port, one part number serves a wider range of repair situations, which simplifies shelf stock for a distributor or a maintenance store.
3. Repair and replacement. A straight adapter that has been over-tightened or damaged is replaced without re-piping, and the two thread standards on the machine stay as they were designed.
4. Test benches and manifold work. Instrumentation lines and test manifolds use the straight body where flow direction must not change and where a low-resistance run is required.

6. Replacement and Cross-Reference Guide

Identify a replacement by standard, thread and sealing method, never by brand or by the marking on the installed part alone. This is a cross standard adapter, so the port standard at each end must be identified before a replacement is ordered.

Measure these three things on the part you are replacing:

1. The two thread forms. Measure the outside diameter and count the threads per inch on each end. The BSPP end is parallel, with a constant diameter along the thread. The BSPT end tapers, so the diameter reduces towards the nose. Compare the result with the E and F columns of the table. A BSPT adapter is identified by that taper, while a BSPP adapter is identified by its parallel thread and seat.
2. The sealing method on the BSPP end. Check whether the end carries a 60° cone seat that meets a mating cone, or a flat shoulder that takes a bonded seal. On this series the same stud end is machined for the cone, and the bonded seal is added only where the port face is flat.
3. The overall length. Measure L and compare it with the table, because a replacement that is longer than the original may not fit the space between the port and the first hose bend.

Organised by standard rather than by brand:

7. Ordering, Packaging and Delivery

Send the following with your inquiry so that the quotation is exact: series code and full part number (for example 1BT-12-16SP), the thread size on each end, seal material (NBR, FKM or EPDM), whether a bonded seal is required with the order, body material and plating option, and the annual quantity. Where the old part carries no readable marking, send the measured thread sizes and the port type instead, and HENGHUA will confirm the match.

• Packaging: single units in sealed bags, bulk quantities in cartons, and palletised cartons for container loads. Marking and labelling can follow distributor shelf needs or direct-to-line OEM needs.
• Sample orders: samples are available for validation before a production order. State the part numbers and seal material you want evaluated.
• Lead time: confirmed per order, based on size, material and quantity. Custom sizes and drawing-based manufacture follow the same route.
• Documentation: quotations and order confirmations state the part number, both thread sizes, material and seal option, so the delivered part can be checked against the paperwork.

8. FAQ

Q1. What is the difference between BSPP and BSPT, and can they be interchanged? BSPP (G thread) is a parallel thread to ISO 228-1 where the pressure-tight joint is not made on the threads: the 60° cone seat or a bonded seal does the sealing. BSPT (R thread) is a taper thread to ISO 7-1 where the joint is made on the thread flanks and needs a sealant. They must never be forced together, because the pitch and the taper differ and forcing one into the other deforms both parts. This series exists so that each port receives the thread form it was made for.

Q2. What is the difference between a 60° cone seat and a bonded seal, and which should I choose? The 60° cone seat seals metal-to-metal against the mating cone inside an ISO 1179 port and needs no separate sealing part. A bonded seal (Dowty-type washer) seals against a flat face and is used when the port has no cone. Choose the cone seat where the mating port is a cone seat port, and the bonded seal where the port face is flat. This series covers both cases with the same BSPP stud end, so the decision is made at the port, not at the part number stage.

Q3. How do I identify the correct 1BT-SP size? Read the two size codes in the part number. The first code is the BSPP (G) thread size and the second code is the BSPT (R) thread size, with 02 = 1/8″, 04 = 1/4″, 06 = 3/8″, 08 = 1/2″, 12 = 3/4″, 16 = 1″, 20 = 1.1/4″, 24 = 1.1/2″, 32 = 2″, 40 = 2.1/2″ and 48 = 3″. When only one code is present, both ends are the same nominal size. Confirm both threads against the ports with a gauge before ordering.

Q4. What seal material should I select for my fluid and temperature? NBR suits general hydraulic oil service at approximately -30°C to +100°C, FKM covers higher temperatures and aggressive media at approximately -20°C to +200°C, and EPDM covers water and water-glycol service at approximately -40°C to +120°C. Select on the fluid and the highest temperature the seal will see, not on ambient temperature. Send the fluid and temperature data with your inquiry and HENGHUA will confirm the selection.

Q5. How is the working pressure of this adapter determined? Working pressure depends on the thread size, the wall thickness of the body, the sealing method and the material selected, so the series is not published with a single figure. Working pressure for these sizes is confirmed per order by HENGHUA engineering, based on the sealing method, thread size and material selected. Include the operating pressure and the fluid in your inquiry so the confirmation can be issued with the quotation.

Q6. What is the minimum order quantity and can I get samples? Samples are available for validation before a production order, and smaller quantities can be supplied for trials and maintenance stock. State the part numbers, seal material and quantity in your inquiry so that sample and production lead times can be confirmed together. Minimum order quantity is confirmed per order according to the size, material and plating combination requested.

Q7. Should I order the bonded seal with the adapter? Order it together when the port face is flat, because the bonded seal is the sealing element in that arrangement and the joint cannot be completed without it. State the seal material with the part number so that the washer and the adapter arrive as one matched set. Where the port has a machined 60° cone, no bonded seal is used and the adapter seals on the seat.

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