Not sure which fitting you need? Tell us what you have, we show you what screws onto it — live prices and stock.
Pipe thread chart: inch / mm conversion (BSP, 15/21, 20/27, S60x6)
A “1/2 inch” thread measures 20.96 mm, not 12.7: in plumbing, the inch size is not converted, it is read from a chart. Here you will find the inch / mm correspondence of every common thread (BSP or “gas thread”, French names 15/21 · 20/27 · 26/34, NPT, S60x6 IBC tanks, Guillemin, Camlock, PVC), a tool that identifies your thread and the fitting that goes with it, and the pitfalls to avoid.
Which thread do you have? Which fitting do you need?
No need to know the name of your thread. Tell us what you need to connect to, or type what you know (“20/27”, “3/4 inch”, “S60x6”, “26.4 mm”): we identify the thread and show you the fittings that go with it. Dimensions according to ISO 228, ISO 7 and ASME B1.20.1.
✔ Shipped next working day from our stock✔ 4.5/5 from more than 6,400 customer reviews✔ Not sure? Describe what you need, we will find the fitting with you⎙ Printable thread gauge (PDF, actual size)
No need to know the name of your thread. Just answer the question: what do you need to connect to?
With a caliper, measure the outside diameter of a male (thread visible on the outside) or the inside diameter of a female (thread inside the hole), at the root of the thread.
The symmetrical Guillemin reducing coupling with locks in aluminum is the perfect solution for safely adapting your pipe diameters. Made in France , this robust coupling enables watertight transition between two hose or valve sizes thanks to its 360° double locking system....
The symmetrical Guillemin reducing coupling with locks in aluminum is the perfect solution for safely adapting your pipe diameters. Made in France , this robust coupling enables watertight transition between two hose or valve sizes thanks to its 360° double locking system....
The symmetrical Guillemin stainless steel reduction fitting with latches is the key part for adapting your pipe diameters safely. Made of heavy-duty stainless steel, it allows for a smooth transition between two nominal sizes while ensuring two-sided mechanical locking....
The symmetrical Guillemin stainless steel reduction fitting with latches is the key part for adapting your pipe diameters safely. Made of heavy-duty stainless steel, it allows for a smooth transition between two nominal sizes while ensuring two-sided mechanical locking....
Symmetrical Guillemin reduction fitting in high-quality polypropylene, equipped with secured locks for reliable and watertight assembly. Designed for fire professionals and demanding industrial applications, this reduction fitting allows connecting two hoses of different diameters with perfect sealing. Material...
Symmetrical Guillemin reduction fitting in high-quality polypropylene, equipped with secured locks for reliable and watertight assembly. Designed for fire professionals and demanding industrial applications, this reduction fitting allows connecting two hoses of different diameters with perfect sealing. Material...
The Guillemin symmetrical reduction coupling with locks in copper alloys (Reference: 101391) is designed to connect hoses of different diameters in professional applications. Made from high-quality brass, it ensures perfect sealing and exceptional corrosion resistance. Its secure locks ensure quick and reliable assembly, ideal for...
The Guillemin symmetrical reduction coupling with locks in copper alloys (Reference: 101391) is designed to connect hoses of different diameters in professional applications. Made from high-quality brass, it ensures perfect sealing and exceptional corrosion resistance. Its secure locks ensure quick and reliable assembly, ideal for...
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