The fitting for when two threads have to meet and do not match — different forms, different sizes, or both. Male/female in any combination, BSPP or NPT at each end, to 420 bar in SS316 and carbon steel A105 — without rebuilding the surrounding pipework.
State both ends with male/female (e.g. 1/2″ BSPP male × 1″ NPT female), material, fluid, working pressure & temperature — quotes back within 2 working hours.
| Range | 1/8″ – 2″ — the ends need not match |
|---|---|
| Threads | BSPP · NPT — any combination |
| Pressure | To 420 bar at 37 °C — subject to temperature derating |
| Materials | SS316 (A479/A276 · A182 F316) · A105 · brass |
| Manufacture | Straights: turned from cold-drawn bar · elbows/tees: close-grain forgings |
| Styles | M×F adapters · hex nipples · plugs · 90° elbows · tees · reducing nipples |
Full dimensions per configuration are in the catalogue below, as printed — the temperature derating and seal limits are on this page.
| At a glance | Adapter | Hex bush |
|---|---|---|
| Ends | Any combination | Male always larger |
| Sizes | Any — female may be larger | Steps up only |
| Thread forms | Can mix BSPP↔NPT | One form |
Material grades and body temperature limits
| Material | Bar stock | Forging | Max body temp |
|---|---|---|---|
| SS316 | ASTM A479 / A276 Type 316 | ASTM A182 F316 | 537 °C |
| Carbon steel | ASTM A108 / JIS G4051 S20C–S45C | ASTM A105 / JIS G3201 SF440A | 204 °C |
| Brass | ASTM B16 C36000 / JIS H3250 C3604 | ASTM B283 C37700 / JIS H3250 C3771 | 190 °C |
Pressure derating by temperature multiplier
| Temperature | SS316 | Carbon steel | Brass |
|---|---|---|---|
| 38 °C (100 °F) | 1.000 | 1.000 | 1.000 |
| 93 °C (200 °F) | 1.000 | 0.940 | 0.780 |
| 149 °C (300 °F) | 1.000 | 0.900 | 0.690 |
| 204 °C (400 °F) | 0.960 | 0.860 | 0.130 |
Seal temperature limits
| Seal | Material | Min | Max |
|---|---|---|---|
| SAE O-ring | FKM | −28 °C | +204 °C |
| Bonded seal | NBR | −25 °C | +110 °C |
| Bonded seal | FKM | −15 °C | +204 °C |
| Copper gasket | Copper | −198 °C | +204 °C |
Reading the tables: an SS316 adapter at PN 420 running at 204 °C = 420 × 0.960 = 403 bar. Where a seal is fitted, the seal limit governs, not the body — even sealed SS316 tops out at 204 °C (NBR at 110 °C; copper for cryogenics to −198 °C).
| Part | Ends | Size change | Use it for |
|---|---|---|---|
| Coupling | Female × female (equal) | None | A straight connector |
| Reducing coupling | Female × female (unequal) | Reduces | Larger pipe to smaller |
| Hex bush | Female × male | Male always larger | Stepping a port up |
| Adapter | Any combination | Any — female may be larger | Mismatched sizes, mixed threads, big jumps |
Bridging two thread forms (BSPP ↔ NPT) without rebuilding the run.
Between tube and pipe sizes in process control and power instrumentation.
Big size jumps with one part instead of a stack of bushes.
Plugs and hex-socket head plugs with bonded seals.
Dimensions and part numbers are in the catalogue, as printed; stock and price are not — send the list and we confirm both.
A coupling joins two pipes of the same size in line (female both ends), no flow area change. An adapter handles mixed male/female, mixed thread forms, a female larger than the male, or big size jumps.
A hex bush always has the male end larger than the female. Need the female larger, or both ends equal? A bush cannot do it — an adapter can.
Yes — stocked and machined, saving one threaded joint compared to a nipple-plus-adapter solution.
A nominal pressure of 420 bar at 37 °C ambient — not the pressure at elevated temperature. Multiply by the derating factor for the actual working pressure.
Material-dependent: SS316 loses nothing to 149 °C (4% at 204 °C); carbon steel is down 6% at 93 °C, 14% at 204 °C; brass loses 22% by 93 °C and collapses after. Above 204 °C, only SS316 applies.
Body limits: SS316 537 °C, carbon steel 204 °C, brass 190 °C. But a sealed adapter is capped by its seal — typically 204 °C (NBR 110 °C; copper to −198 °C).
NBR for ordinary duty to 110 °C; FKM to 204 °C; copper for extreme cold to −198 °C. State the fluid too — solvents and steam rule out certain materials.
Straight parts are turned from cold-drawn bar with aligned grain. Directional changes need close-grain forging to keep the metal sound around the corners.
Yes — machined to order, often faster than redesigning the pipework. Send both ends and a sketch if the geometry is unusual.
The ideal format: “1/2″ BSPP male × 1″ NPT female, SS316, 250 bar at 120 °C” — or describe what is on the machine and what is on the pipe.
Yes — common combinations in our regional warehouses in Singapore and Malaysia, out within 24 hours; machined parts quoted with lead time. Quotes within 2 working hours.
Related: forged pipe fittings · JIC fittings · bonded seals · all high pressure fittings · baca halaman ini dalam Bahasa Indonesia
