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.
Symmetric Guillemin half coupling with lock in polypropylene with male threaded socket. Designed for firefighting and industrial applications , this high-performance coupling integrates BSP gas threading for reliable and leak-proof connection. Perfect for suction and discharge of liquids,...
Symmetric Guillemin half coupling with lock in polypropylene with male threaded socket. Designed for firefighting and industrial applications , this high-performance coupling integrates BSP gas threading for reliable and leak-proof connection. Perfect for suction and discharge of liquids,...
The symmetrical connection with reduced ringed socket with polypropylene collar is intended to be crimped on pipes. It can be assembled by different crimping systems: stamped skirts, ruffled necklaces, strapping and notched...
The symmetrical connection with reduced ringed socket with polypropylene collar is intended to be crimped on pipes. It can be assembled by different crimping systems: stamped skirts, ruffled necklaces, strapping and notched...
The symmetrical Guillemin firefighter cap in polypropylene with lock and chain guarantees perfect sealing of your symmetrical fittings. Designed for professionals and individuals, it effectively protects against infiltration, dust and contamination. Its polypropylene construction ensures excellent chemical and mechanical...
The symmetrical Guillemin firefighter cap in polypropylene with lock and chain guarantees perfect sealing of your symmetrical fittings. Designed for professionals and individuals, it effectively protects against infiltration, dust and contamination. Its polypropylene construction ensures excellent chemical and mechanical...
The Guillemin Female Symmetrical Polypropylene Half Fitting with Lock provides exceptional chemical resistance for the transfer of aggressive fluids. Featuring a standard BSP tap, it easily adapts to your fixed installations while ensuring secure mechanical locking. Ideal for agriculture, water...
The Guillemin Female Symmetrical Polypropylene Half Fitting with Lock provides exceptional chemical resistance for the transfer of aggressive fluids. Featuring a standard BSP tap, it easily adapts to your fixed installations while ensuring secure mechanical locking. Ideal for agriculture, water...
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...
IBC 1000 L accessories 
Heating jackets 
Fittings 
Drums, jerrycans & fittings 
Seeds 
Plant protection & biocides 
Garden 
Green spaces & municipal 
Barbecue, fire pit & fireplace 
Cleaning & care 
Refrigerants & air conditioning 
Watering 
