The TUPY Brazil lock nut (figure 312) is run onto a pipe thread to lock a component in a set position, or to stop a joint working loose under vibration.
| Figure number | 312 |
| Size range | 3/8" – 3" |
| Finish | Galvanised and black |
| Thread | BSP (ISO 7-1) |
| Standard | ISO/EN/NBR P4 |
| Maximum working pressure | 25 bar (−20 to +120°C); 20 bar at +300°C — verify application |
| Material | Malleable cast iron |
The size range summarises this figure's table and does not guarantee stock in every size. TUPYBSP working pressure is 25 bar from −20 to +120 °C; consult the catalogue pressure–temperature table outside that range. Hydrostatic test values are not working pressures; the catalogue specifies a separate 37.5 bar test value for joints. Check the product-family catalogue and the required figure and size approvals before selection.
These marks relate to TUPY product-line standards and approvals. Scope varies by figure, size and application; confirm the current catalogue and figure-specific listing before specification.
The dimension letters follow the technical drawing above. Weights are per single fitting, in kilograms.
| Nominal diameter | Dimensions (mm) | Weight (kg) | |||
|---|---|---|---|---|---|
| inch | mm | a | s | Galvanised | Black |
| 3/8" | 10 | 8 | 27 | 0.023 | 0.021 |
| 1/2" | 15 | 9 | 32 | 0.031 | 0.029 |
| 3/4" | 20 | 10 | 36 | 0.036 | 0.035 |
| 1" | 25 | 11 | 46 | 0.065 | 0.062 |
| 1.1/4" | 32 | 12 | 55 | 0.099 | 0.094 |
| 1.1/2" | 40 | 13 | 60 | 0.110 | 0.104 |
| 2" | 50 | 14 | 75 | 0.174 | 0.165 |
| 2.1/2" | 65 | 17 | 95 | 0.355 | 0.348 |
| 3" | 80 | 20 | 105 | 0.413 | 0.399 |
Source: TUPY catalogue dimensional data for this figure; verify the current revision.
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Send us the figures and sizes you need and our Dubai office will come back with a quotation, stock position and lead time.
When a component has to stay at a particular angle or height on a thread — where a pipe passes through a wall, when fixing a valve, or when mounting a flange — screwing the thread fully home will not hold it where you want it. The lock nut bears against the component from behind and locks it in place.
Its second use is to hold a joint against gradually working loose on lines that vibrate.
The thread on this figure is to ABNT NBR 8133 and ISO 228. Sizes run from 3/8 to 3in.
Sample dimensions: ⅜in code 1206003, thickness a = 8 and across flats s = 27 mm; ½in code 1206004, a = 9, s = 32; 1in code 1206007, a = 11, s = 46; 2in code 1206010, a = 14, s = 75; and 3in code 1206012, a = 20, s = 105 mm. Galvanised weight runs from 0.023 to 0.413 kg.
The material is blackheart malleable cast iron to grade JMB 350-10, finished hot-dip galvanised or black.
The TUPY Brazil Lock Nut is made in 9 sizes, from 3/8" to 3". The full list of sizes, with the dimensions in millimetres and the weight of each piece, is in the dimensions and weights table on this page.
The weight depends on the size: the 1" size, for example, weighs 0.065 kg galvanised and 0.062 kg black. The weights of every size are taken from the official TUPY catalogue and are listed in the table on this page, so they can be used to work out shipping weight and freight cost.
TUPYBSP fittings are threaded to BSP in accordance with ISO 7-1; the male thread is tapered and the seal is made on the thread itself. BSP is not interchangeable with NPT, and screwing the two together will leak. TUPY also produces a separate NPT line, which is covered in the downloads section.
According to TUPY's technical catalogue, the working pressure of TUPYBSP fittings is 25 bar between −20 °C and +120 °C. For temperatures outside that interval, use the catalogue pressure-temperature table and confirm suitability for the application. The catalogue lists hydrostatic design-test pressures of 100 bar for other fittings from 1/4 in to 4 in, 64 bar for 5 in and 6 in, and 37.5 bar for joints. These are test values, not working-pressure ratings. Confirm the applicable fitting, temperature range and project requirements before selection.
The TUPY Lock Nut is manufactured to ISO/EN/NBR P4. TUPY malleable cast iron fittings are built to ISO 49, EN 10242 and ABNT NBR 6943, and their threads follow ISO 7-1. Check the current figure- and size-specific listing before relying on an approval.
Where dimensions permit, genuine TUPY fittings carry cast markings such as the factory mark and nominal size. Check the figure-specific catalogue and packaging as well. The threads are clean and free of burrs, and the galvanised coating is even. The surest check is to weigh the piece and compare it with the weight table on this page; counterfeit pieces usually come out lighter than the official catalogue weight.
Use the request a quote page at /request-a-quote and tell us the figure number (312), the sizes and the quantities you need. Our Dubai office will come back with a quotation, the current stock position and a lead time. Amini Building Materials Trading L.L.C is the exclusive agent of TUPY S.A. in the Middle East and supplies the region from Dubai.
