Stainless steel half socket, female/female 316, BSP threaded
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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
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Stainless steel half socket, female/female 316, BSP threaded
Stainless steel half socket, female/female 316, tapped BSP (Rp to ISO 7-1) at both ends, from 1/4" to 4" (DN8 to DN100). This threaded stainless steel coupling is shorter than the machined coupling of the same size: compare dimension L in the tables. It is rated PN 20 up to 40 °C and drinking water compliant, for all fluids compatible with stainless steel.
Description of the stainless steel BSP half socket
This threaded stainless steel pipe fitting has an Rp tapped thread at each end, over a short length. Machined from AISI 316 stainless steel, it has a smooth cylindrical body with no flats or end bands. The parallel Rp tapped thread fits onto a taper R male thread. The 1/2" corresponds to French size 15x21, i.e. DN15.
Compared with the machined version of the stainless steel female/female coupling, the difference is the length: the half socket is roughly half as long. At 1/2", the half socket measures Ø 25 × 17 mm and weighs 22 g; the machined coupling measures Ø 25 × 32.5 mm and weighs 44 g.
Stainless steel half socket: technical specifications
| Material | AISI 316 stainless steel |
| Manufacture | Machined part |
| Standard | ISO 4144 |
| Exterior | Smooth and cylindrical, no flats |
| Thread | Rp tapped (parallel) to ISO 7-1 (BSP, R series). Mates with an R male thread (taper). Not compatible with NPT |
| Connection | Female/female |
| Nominal pressure | PN 20: 20 bar from −20 to 40 °C, lower above that |
| Temperature | −20/+220 °C, permissible pressure reduced above 40 °C |
| Fluids | All fluids compatible with stainless steel |
| Sizes | 11 sizes, from 1/4" to 4" |
| Compliance | 4MS; drinking water: French order of 25 June 2020 |
Pressure and temperature
PN 20 applies from −20 to 40 °C. Above that, the permissible pressure falls. Values marked ≈ are read from the pressure/temperature curve in the technical data sheet.
| Temperature (°C) | Max. pressure (bar) |
|---|---|
| −20 → 40 | 20 |
| 100 | ≈ 16.5 |
| 150 | ≈ 15 |
| 220 | ≈ 13.5 |
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 half socket is used on drinking water systems and on circuits carrying fluids compatible with 316 stainless steel. Where the joint must be removable, choose a stainless steel union instead. Check fluid compatibility and the permissible pressure at the working temperature.
- Thread length: its short length limits the thread engagement available at each end. To connect two opposing R male threads, use the stainless steel female/female coupling instead. Whether two male threads can be fitted into this half socket depends on the size, the thread lengths and the engagement needed for a tight seal.
- Thread sealing: an Rp/R joint seals on the threads, using PTFE or jointing compound suited to the fluid and the working temperature.
- Galling: with stainless steel on stainless steel, the thread can gall. Screw in gradually, without forcing.
- Tightening: tighten with an open-ended or adjustable spanner on the flats of the male component (a strap wrench on pipe), not with pipe grips or pliers, which mark stainless steel. As the half socket has no flats, hold it with a strap wrench.
- Dissimilar metals: on a water system, stainless steel forms a galvanic couple with galvanized steel or cast iron. Allow for this when choosing the connected components.
Technical drawing
Dimensions (mm)
Dimensions in millimetres, PN in bar, weight in kilograms. ØA is the outside diameter of the body and L its length. Dimension L for the 3/4" is not currently available: contact us if you need it.
| Rp size | French size | ØA | L | PN (bar) | Weight (kg) |
|---|---|---|---|---|---|
| 1/4" | 8x13 | 16.5 | 12 | 20 | 0.009 |
| 3/8" | 12x17 | 20 | 13.5 | 20 | 0.010 |
| 1/2" | 15x21 | 25 | 17 | 20 | 0.022 |
| 3/4" | 20x27 | 32.5 | – | 20 | 0.032 |
| 1" | 26x34 | 37.5 | 20.5 | 20 | 0.046 |
| 1"1/4 | 33x42 | 47 | 24 | 20 | 0.080 |
| 1"1/2 | 40x49 | 54.5 | 22.5 | 20 | 0.107 |
| 2" | 50x60 | 66 | 26 | 20 | 0.157 |
| 2"1/2 | 66x76 | 82 | 32 | 20 | 0.253 |
| 3" | 80x90 | 96.5 | 34.5 | 20 | 0.374 |
| 4" | 102x114 | 121 | 40.5 | 20 | 0.533 |
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 | 8x13 | 12x17 | 15x21 | 20x27 | 26x34 | 33x42 | 40x49 | 50x60 | 66x76 | 80x90 | 102x114 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Inches | 1/4" | 3/8" | 1/2" | 3/4" | 1" | 1"1/4 | 1"1/2 | 2" | 2"1/2 | 3" | 4" |
| DN | DN8 | DN10 | DN15 | DN20 | DN25 | DN32 | DN40 | DN50 | DN65 | DN80 | DN100 |
| OD (French size) | 13 mm | 17 mm | 21 mm | 27 mm | 34 mm | 42 mm | 49 mm | 60 mm | 76 mm | 90 mm | 114 mm |
Stainless steel half socket: frequently asked questions
What is the difference between a half socket and a machined coupling?
The length (the half socket is roughly half as long), and therefore the weight. The outside diameter is similar: compare dimension ØA on the two product pages. The material, PN and Rp tapped thread are the same.
What is the pressure rating at 100 °C?
≈ 16.5 bar, against 20 bar from −20 to 40 °C.
BSP or NPT thread?
BSP to ISO 7-1: Rp parallel tapped thread, for use with an R taper male thread. This half socket is not compatible with NPT.
316 or 304 stainless steel?
This half socket is AISI 316. Unlike 304, 316 contains molybdenum and has better resistance to chlorides.
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: stainless steel female/female coupling, stainless steel male/male nipple, stainless steel male hose tail, stainless steel union PN 20.
Other materials: brass couplings, black malleable iron couplings.
Useful guides:
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