Stainless steel union, male/male 316L, PN 40, BSP threaded
Shipping and Delivery
Shipping and Delivery
| Product Type | Delivery Method | Preparation Time | Transport Time | Delivery Time |
|---|---|---|---|---|
| All Parts | Pickup Point | 0 to 3 days | 3 to 6 days | 3 to 9 days |
| All Parts | Home Delivery | 0 to 3 days | 3 to 5 days | 3 to 8 days |
| Tubes > 90cm | Home Delivery | 0 to 3 days | 3 to 5 days | 3 to 8 days |
| Tubes < 200cm | Home Delivery | 0 to 3 days | 3 to 5 days | 3 to 8 days |
| Tubes > 200cm | Home Delivery | 0 to 6 days | 6 to 10 days | 6 to 16 days |
| Assembled Products | Home Delivery & Pickup Point | 0 to 5 days | (see methods) | 3 to 11 days |
* Tubes longer than 90cm cannot be delivered to a pickup point
For orders of more than 50 units of the same item or more than 100 kg, restocking may exceptionally extend the delivery time by up to 10 working days.
For confirmation of delivery times on specific items, please send us a message
Stainless steel union, male/male 316L, PN 40, BSP threaded
Stainless steel union, male/male 316L, PN 40, threaded BSP (R taper to ISO 7-1) at both ends, from 1/2" to 2" (DN15 to DN50). This machined conical (taper) seat union joins two Rp tapped components and lets you separate them without unscrewing them. PN 40, drinking water compliant, for all fluids compatible with stainless steel.
Description of the machined stainless steel male/male union 316L
This 3-piece stainless steel union comprises two male ends in 316L stainless steel, the low-carbon version of 316, and a CF8M stainless steel nut. At the conical seat, the seal is metal to metal. The nut unscrews to open the joint, and each end stays in its tapped port.
One end is 6-sided. The other is cylindrical, with spanner flats. This union has no weld end: for a weld end on one side, see the stainless steel union, male/butt weld, PN 40.
Stainless steel male/male union 316L PN 40: technical specifications
| Material | 316L stainless steel ends, CF8M stainless steel nut |
| Manufacture | Machined conical (taper) seat union |
| Standard | ISO 4144 |
| Type | 3-piece: two ends and a nut |
| Seal at the seat | Metal to metal |
| Shape | One end 6-sided, the other cylindrical with spanner flats |
| Thread | R (taper) at both ends, to ISO 7-1 (BSP). Mates with an Rp female thread (parallel). Not compatible with NPT |
| Connection | Male/male |
| Nominal pressure | PN 40. Permissible pressure falls as temperature rises |
| Temperature | Stated range −20/+220 °C, with no high-temperature pressure values: consult us for hot applications |
| Fluids | All fluids compatible with stainless steel |
| Sizes | 6 sizes, from 1/2" to 2" |
| Compliance | 4MS; drinking water: French order of 25 June 2020 |
Pressure and temperature
This union is rated PN 40. The permissible pressure falls as temperature rises, and we have no high-temperature pressure curve for this part. The stated range of −20 to +220 °C therefore does not mean PN 40 across the whole range. For hot applications, contact us before choosing.
Certification and compliance
According to the technical data sheet for the series:
- 4MS: compliant with the 4MS requirements, the harmonized European rules for materials and products in contact with drinking water.
- Drinking water: compliant with the French order (arrêté) of 25 June 2020 on metallic materials and products in contact with water intended for human consumption.
Uses and installation advice
This union is used on drinking water systems and on circuits carrying fluids compatible with stainless steel, between two tapped components that must stay removable. Check the fluid’s compatibility with 316L and CF8M. For a joint that never needs to be opened, see the stainless steel male/male nipple, rated PN 20.
- Assembly: separate the ends and screw each one into its tapped port with an open-ended or adjustable spanner (hexagon or spanner flats), not with pipe grips or pliers, which mark stainless steel. Bring them together, then tighten the nut.
- Thread sealing: an Rp/R joint seals on the threads, using PTFE or jointing compound suited to the fluid and the temperature.
- Conical seat: keep it clean at every assembly.
- Galling: with stainless steel on stainless steel, the thread can gall. Screw in gradually, without forcing.
- Dissimilar metals: on a water system, stainless steel forms a galvanic couple with galvanized steel or cast iron.
Technical drawing
Dimensions (mm)
Dimensions in millimetres, PN in bar, weight in kilograms. M1: length of the nut. M2: length of the 6-sided section. L: overall length of the part.
| R size | French size | M1 | M2 | L | PN (bar) | Weight (kg) |
|---|---|---|---|---|---|---|
| 1/2" | 15x21 | 16 | 9 | 65 | 40 | 0.142 |
| 3/4" | 20x27 | 17 | 9 | 68 | 40 | 0.212 |
| 1" | 26x34 | 18 | 9 | 76 | 40 | 0.305 |
| 1"1/4 | 33x42 | 18 | 10 | 81 | 40 | 0.381 |
| 1"1/2 | 40x49 | 18 | 10 | 82 | 40 | 0.512 |
| 2" | 50x60 | 20 | 12 | 95 | 40 | 0.716 |
Size conversion
Conversion between the French size designation, inches, DN and the outside diameter stated in the designation (a rounded value, not a pipe dimension).
| French size | 15x21 | 20x27 | 26x34 | 33x42 | 40x49 | 50x60 |
|---|---|---|---|---|---|---|
| Inches | 1/2" | 3/4" | 1" | 1"1/4 | 1"1/2 | 2" |
| DN | DN15 | DN20 | DN25 | DN32 | DN40 | DN50 |
| OD (French size) | 21 mm | 27 mm | 34 mm | 42 mm | 49 mm | 60 mm |
Stainless steel male/male union 316L PN 40: frequently asked questions
Male/male, male/female or female/female?
This union screws into an Rp tapped port at each end. The male/female union PN 40 screws in at one end and takes an R male thread at the other. The female/female union PN 40 takes an R male thread at each end.
Is this union available in PN 20?
No, in our range the male/male version only comes in PN 40. For PN 20, see the female/female union and the male/female union.
What is the pressure rating at high temperature?
We have no figure for this part. Contact us with the size, fluid, temperature and working pressure.
BSP or NPT thread?
BSP to ISO 7-1: R taper, for use with an Rp parallel female thread. This union is not compatible with NPT.
The appearance of the part may vary depending on the batch in stock. Contact us for confirmation.
See also
Full range: all stainless steel BSP fittings
Other stainless steel fittings: male/female union PN 40, female/female union PN 40, male/butt weld union PN 40.
Other materials: brass fittings, black malleable iron unions.
Useful guides:
Payment & Security
Payment Method
Your payment information is managed securely. We do not store or have access to your credit card information.