SS 304/304L forged fittings are socket weld and threaded fittings forged and machined from ASTM A182 / ASME SA182 F304 and F304L stainless steel to the dimensions of ASME B16.11. They join small-bore stainless pipe, from ⅛" to 4", in water, steam condensate, instrument air, food and pharmaceutical utilities and general chemical service.
Raaj Fittings forges SS 304/304L elbows, tees, couplings, unions, caps, plugs, bushings and nipples in-house at our two plants in India, in Class 2000, 3000, 6000 and 9000, and exports them to fabricators and stockists across the Middle East, Europe and the Americas. Dual-certified F304/F304L is the standard supply.
| Material specification | ASTM A182 / ASME SA182 F304, F304L; dual-certified F304/F304L |
|---|---|
| Dimensional standard | ASME B16.11; MSS SP-79 (reducer inserts), MSS SP-83 (unions), MSS SP-95 (swage nipples, bull plugs), MSS SP-97 (branch outlets) |
| Size range | ⅛" to 4" NPS |
| Pressure class | Socket weld: Class 3000, 6000, 9000. Threaded: Class 2000, 3000, 6000 |
| Threads | NPT to ASME B1.20.1; BSPT / BSPP to BS 21 / ISO 7-1 |
| Manufacturing | Forged from bar or billet, solution annealed and CNC machined |
| Certification | EN 10204 3.1 mill test certificate as standard; EN 10204 3.2 on request |
| Element, % | F304 | F304L |
|---|---|---|
| Carbon (C) | 0.08 max | 0.030 max |
| Manganese (Mn) | 2.00 max | 2.00 max |
| Phosphorus (P) | 0.045 max | 0.045 max |
| Sulphur (S) | 0.030 max | 0.030 max |
| Silicon (Si) | 1.00 max | 1.00 max |
| Chromium (Cr) | 18.0 – 20.0 | 18.0 – 20.0 |
| Nickel (Ni) | 8.0 – 11.0 | 8.0 – 12.0 |
| Nitrogen (N) | 0.10 max | 0.10 max |
| Property (min.) | F304 | F304L |
|---|---|---|
| Tensile strength | 515 MPa (75 ksi) | 485 MPa (70 ksi) |
| Yield strength (0.2% offset) | 205 MPa (30 ksi) | 170 MPa (25 ksi) |
| Elongation in 50 mm | 30% | 30% |
| Reduction of area | 50% | 50% |
| Grade | UNS | Werkstoff Nr. | EN designation | JIS |
|---|---|---|---|---|
| 304 | S30400 | 1.4301 | X5CrNi18-10 | SUS 304 |
| 304L | S30403 | 1.4307 / 1.4306 | X2CrNi18-9 / X2CrNi19-11 | SUS 304L |
ASME B16.11 matches each fitting class to a pipe wall so the fitting is at least as strong as the pipe:
| Pipe | Socket weld class | Threaded class |
|---|---|---|
| SCH 80 / XS | 3000 | 2000 |
| SCH 160 | 6000 | 3000 |
| XXS | 9000 | 6000 |
Light-wall stainless lines in SCH 10S or 40S are still joined with Class 3000 socket weld fittings, the lightest socket weld class, because the fitting wall is set by the class rather than the pipe.
Socket weld fittings give a leak-tight, permanent joint and are preferred in process lines. Threaded 304 fittings are used where welding is impractical, on instrument and utility connections, and for drains and vents; stainless threads can gall, so a suitable anti-seize thread sealant is recommended. For chloride-bearing water or salt atmospheres, choose SS 316/316L forged fittings instead.
Every heat is PMI-verified and its chemistry and mechanical properties are confirmed against the material specification before the fittings are released. Each piece is marked with grade, size, rating and heat number for traceability to its EN 10204 3.1 mill test certificate. EN 10204 3.2 certification and inspection by the buyer's nominated third-party agency are available on request, as are PED 2014/68/EU compliance for European projects and IBR certification for Indian boiler applications.
We make SS 304/304L socket weld and threaded fittings from ⅛" to 4" NPS to ASME B16.11. In practice most small-bore stainless piping uses ½" to 2" fittings.
Use Class 3000 socket weld fittings with SCH 80 pipe, Class 6000 with SCH 160 and Class 9000 with XXS. For threaded fittings the matching classes are 2000, 3000 and 6000.
Austenitic stainless steel threads can gall when tightened dry, because the surfaces cold-weld under pressure. Using a suitable anti-seize thread sealant and not over-tightening prevents this.
Yes, they are normally supplied dual-certified F304/F304L, meeting the strength of F304 and the 0.030% carbon limit of F304L, with EN 10204 3.1 certificates.