A variety of steel British Standard Pipe Taper (BSPT) fittings on a workbench, with a focus on the tapered R-threads that create a seal.

BSPT (R/Rc Thread) Pipe Fittings – Steel

The British Version of a Tapered Pipe Thread. And No, It's Not the Same as NPT.

Think of It Like an NPT with an Accent.

If you're used to American pipe threads, the BSPT (British Standard Pipe Taper) will feel familiar. Just like an NPT fitting, it's got tapered threads, and it's designed to seal by brute force—the male and female threads wedge themselves together as you tighten them. It's the standard for tapered threads on a ton of international equipment, governed by the ISO 7-1 rulebook.

Here's the Catch: Sealant is Not Optional. Just like an NPT, there's a tiny spiral leak path built into the design. To get a reliable, pressure-tight seal, you absolutely must use a quality thread sealant like PTFE tape or paste on the male threads. Don't skip this step.

The key thing to remember is that while it *works* like an NPT, it is not dimensionally the same. We forge our steel BSPT fittings to the exact ISO standard to make sure they work right with the equipment they're designed for. Explore our adapters and plugs below.

BSPT Fitting & Adapter Catalog (Steel)

BSPP Male x BSPT Male Adapter

Part #: 9003

Straight adapter connecting a female BSPP port (using bonded seal) to a female BSPT port (seal on threads).

BSPT Male x NPTF Male Adapter

Part #: 9008

Straight adapter connecting a female BSPT port to a female NPTF port. Note thread angle difference (55° vs 60°).

JIC Male x Female BSPT Adapter

Part #: 9009

Straight adapter connecting a male BSPT pipe/fitting to a female JIC swivel fitting/tube.

BSPT Male x BSPT Male Union

Part #: 9010

Straight union connecting two female BSPT ports. Male BSPT threads on both ends.

JIC Male x BSPT Male Adapter

Part #: 9011

Straight adapter connecting a female JIC swivel/tube to a female BSPT port.

BSPT Hex Head Plug

Part #: 9030T

Seals a female BSPT port. Male BSPT thread with external hex head for wrench tightening.

BSPT Hex Socket Plug (Hollow)

Part #: 9030TCSP

Seals a female BSPT port. Male BSPT thread with internal hex socket drive, possibly hollow for specific uses.

BSPT Male x Female BSPT Bushing

Part #: 9031

Reducer bushing connecting different BSPT thread sizes. Male BSPT external, smaller Female BSPT internal.

BSPT Male x Female BSPP Adapter

Part #: 9032

Straight adapter connecting a male BSPP fitting into a female BSPT port.

BSPT Male x Female BSPP Swivel Adapter

Part #: 9032S

Straight adapter connecting a male BSPP fitting to a female BSPT port, featuring a swivel nut.

BSPP Male x Female BSPT Adapter

Part #: 9034

Straight adapter connecting a male BSPT pipe/fitting into a female BSPP port (using bonded seal).

BSPT Male x Female NPTF Adapter

Part #: 9042

Straight adapter connecting a male NPTF pipe/fitting into a female BSPT port.

BSPP Male x BSPT Male 45° Elbow

Part #: 9054

45° adapter elbow connecting a female BSPP port (bonded seal) to a female BSPT port (thread seal).

BSPT Male to Female BSPP Swivel 90° Elbow

BSPT Male x Female BSPP Swivel 90° Elbow

Part #: 9062

90° adapter elbow connecting a male BSPP fitting to a female BSPT port, featuring a swivel nut.

JIC Male x BSPT Male 90° Elbow

Part #: 9063

90° adapter elbow connecting a female JIC swivel/tube to a female BSPT port.

JIC Male x BSPT Male 45° Elbow

Part #: 9064

45° adapter elbow connecting a female JIC swivel/tube to a female BSPT port.

BSPT Male Tee

Part #: 9086

Connects three female BSPT ports in a tee configuration. All ends Male BSPT.

BSPT Male Cross

Part #: 9097

Connects four female BSPT ports at 90° angles. All ends Male BSPT.

JIC Male x JIC Male x BSPT Male Run Tee

Part #: 9163

Tee adapter connecting two female JIC swivel/tubes on the run and one female BSPT port on the branch.

The Shop Floor Truth on BSPT vs. NPT

Mixing up BSPT and NPT is one of the most common—and frustrating—mistakes a mechanic can make when working on international gear. They look almost the same, but they're different enough to cause a big headache. Here’s the field guide.

How It Works: The Tapered Wedge

A male BSPT thread (called an 'R' thread) is cut on a taper. A female BSPT thread (an 'Rc' thread) is also tapered. When you tighten them, you're literally forcing two metal cones together. This interference fit is what creates the primary seal, and a good thread sealant fills in the microscopic gaps to make it leak-proof.

The Critical Differences You CANNOT Ignore:

Thread Angle: BSPT threads are cut at a 55-degree angle. Our American NPT threads are cut at a 60-degree angle. They will not mate properly.
Thread Pitch: On most sizes, the distance between the threads is slightly different.

The Bottom Line: They Are NOT Interchangeable. You might get one or two turns before they bind up. If you force it past that, you will wreck the threads on both the fitting and the port, guaranteeing a leak and a much bigger repair job. If a fitting doesn't want to thread in by hand, stop and figure out why.

The Good and The Bad (Just Like NPT)

Because it's a tapered thread, it shares all the same pros and cons as its American cousin:

Good: It’s cheap, it’s strong, and it's widely available on international equipment.
Bad: Vibration will work it loose, over-tightening can crack the port, and you shouldn't reuse it over and over again. It’s also a pain to get elbows and tees lined up perfectly.

How to Install it Right

The process is exactly the same as for NPT. No shortcuts.

Clean the threads. Both male and female.
Put sealant on the MALE threads only. Leave the first thread bare.
Start it by hand. Always.
Use two wrenches and tighten it down about 1.5 to 3 turns past hand-tight. You'll feel it seat.
Do NOT back it off to align an elbow. You’ll break the seal.

The Tapered Thread for Your International Gear.

Stocking the right BSPT adapters is critical for servicing equipment built overseas. As the direct factory, we provide distributors and OEMs with the high-quality fittings they need to avoid cross-threading and stop leaks. Let's talk about getting the right parts in your inventory.

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