High-Performance SMO 254 Stainless Steel Fittings & Flanges – Buttweld, Forged, Outlet Types – ISO Certified, NACE MR0175, PED, IBR Compliant.
We are an ISO 9001:2015 certified manufacturer, stockist, and exporter of premium quality SMO 254 (UNS S31254) stainless steel products. Our offerings include a full range of buttweld fittings, flanges, forged fittings, and branch connection olets, all manufactured as per ASTM A403, A182 standards and complying with ASME/ANSI B16.9, B16.5, B16.11, MSS SP-97 dimensions. With strong technical expertise and a global supply network, we cater to critical industries that demand superior corrosion resistance and mechanical strength.
SMO 254 is a high-alloy austenitic stainless steel enriched with 6% molybdenum and nitrogen, offering outstanding resistance to pitting, crevice corrosion, and stress corrosion cracking—especially in chloride-bearing environments. Our SMO 254 buttweld fittings (elbows, tees, reducers, caps) are precision-engineered and available in SCH 10 to SCH XXS. We supply flanges in WNRF, SORF, BLRF, Lap Joint, Threaded, and Blind types, in Class 150, 300, 600, 900, 1500, and 2500 ratings. Forged fittings (socket weld/threaded) are offered in Class 3000, 6000 & 9000, and we also supply olets such as Weldolet, Threadolet, Sockolet, and Latrolet with MSS SP-97 compliance.
SMO 254 is the alloy of choice in extremely corrosive applications, including offshore oil rigs, desalination plants, marine piping, chemical reactors, pulp & paper bleaching systems, and food-grade acid environments. Our SMO 254 fittings and flanges are designed for high-pressure and high-temperature operations, ensuring safety and longevity. Its excellent weldability and formability also make it suitable for complex fabrication requirements in industrial piping systems, tank fabrications, and heat exchangers.
Every SMO 254 product is tested per NACE MR0175, EN 10204 3.1/3.2, and PMI-certified. Third-party inspection and MTCs are provided on request. We maintain large inventories to ensure fast turnaround and ship globally to markets in Europe, the Middle East, North America, and Asia. With compliance to global norms and high-quality manufacturing, we are a trusted supplier of SMO 254 buttweld pipe fittings, forged fittings, flanges, and olets, supporting critical infrastructure with precision-engineered components.
Ready Stock of SMO 254 Flanges & Pipe Fittings in Stock – Including WNRF, SORF, Blind Flanges, Buttweld Elbows, Tees, Reducers & Forged Fittings – Couplings, Unions, Bushings – Plus Weldolet, Sockolet, Threadolet – ASME B16.5, B16.9, B16.11, MSS SP-97 Standards – Pressure Ratings: 150# to 2500#.
Technical Index
Industrial Stainless Steel SMO 254 Specifications
| Material Grade | Stainless Steel SMO 254 / 1.4547 / UNS S31254 |
|---|---|
| Available Product Types | Flanges, Buttweld Fittings, Forged Fittings, Olets |
| Flanges Size Range | ½” (15 NB) to 48” (1200 NB) |
| Class | 150, 300, 600, 900, 1500, 2500, PN6, PN10, PN16, PN25, PN40, PN64 |
| Standard Specifications | ASTM A182, A403 / ASME SA182, SA403 |
| Standards | ASME B16.5, B16.47 Series A & B, B16.48, EN 1092-1, DIN, BS4504, BS10, ISO 7005-1, GOST, JIS B2220, MSS SP-44, API 605 |
| Types | Weld Neck Flange (WNRF), Slip-On Flange (SORF), Socket Weld Flange (SWRF), Threaded Flange, Blind Flange (BLRF), Lap Joint Flange, Ring Type Joint Flange (RTJ), Long Weld Neck Flange, Reducing Flange, Expander Flange, Orifice Flange, Spectacle Blind Flange, Spacer Flange, Paddle Blank, Paddle Spacer, Raised Face (RF), Flat Face (FF), Large Male-Female (LMF), Small Male-Female (SMF), Tongue & Groove |
| Buttweld Fittings Size | ½” NB to 24” NB (seamless), ½” NB to 48” NB (welded) |
| Wall Thickness | SCH 10, SCH 20, SCH 40, SCH 80, SCH 160, XXS |
| Standards | ASME B16.9, MSS SP-75, EN 10253, DIN 2605/2615/2616, ISO 3419, JIS B2312 |
| Types | Elbow (90°, 45°, Long Radius, Short Radius), Tee (Equal & Reducing), Reducer (Concentric & Eccentric), Caps, Stub Ends |
| Forged Fittings Size | ½” NB to 4” NB (Socket Weld & Threaded) |
| Class | Class 2000, 3000, 6000, 9000 (psi) |
| Standards | ASME B16.11, MSS SP-83, MSS SP-95, JIS B2316 |
| Types | 90° Elbow, 45° Elbow, Tee, Cross, Full Coupling, Half Coupling, Pipe Cap, Union, Reducer Insert, Boss, Hex Head Bushing, Hex Head Plug, Square Head Plug, Round Head Plug, Bull Plug, Boss, Outlet, Hex Nipple, Swage Nipple. |
| Olets (Outlet Fittings) Size | Branch Sizes ½” to 24” | Run Pipe Sizes up to 36” (custom) |
| Class | 3000#, 6000#, 9000# |
| Standards | MSS SP-97, ASME B16.11, ANSI, DIN, EN, JIS (custom) |
| Types | Weldolet, Sockolet, Threadolet, Elbolet, Latrolet, Nipolet, Sweepolet, Brazolet |
| End Connection Types | Buttweld, Socket Weld, Threaded (NPT/BSP), Flanged (RF, FF, RTJ), Custom Branch Outlets |
| Testing & Certifications | EN 10204 3.1 & 3.2, NACE MR0175, NACE MR0103, IBR, PMI, Ultrasonic Test, Radiography, Magnetic Particle Inspection |
| Surface Finish Options | Pickled, Passivated, Mirror Finish, Satin Finish, Sandblasted, Coated (Black, Yellow Transparent, Zinc) |
| Manufacturing Capabilities | CNC Machining, Cold/Hot Forming, Beveling, Drilling, Induction Heating, Forging, Custom Fabrication |
| Raw Material Sources | India, Japan, South Korea, USA, Germany, Italy |
| Export Destinations | USA, UAE, Saudi Arabia, Qatar, Kuwait, Oman, Egypt, South Africa, Kenya, Nigeria, Singapore, Malaysia, Australia |
Industrial Stainless Steel SMO 254 Standards
| ANSI/ASME B16.47 Flanges | ANSI/ASME B16.36 Flanges | ANSI/ASME B16.5 Flanges | Pr. EN1902-1 Flanges |
| DIN Flanges | JIS Flanges | BS 4504 Flanges | BS 10 Flanges |
| MSS SP-44 Flanges | JIS B2220 Flanges | KS B1503 Flanges | UNI Flanges |
| SABS/SANS 1123 Flanges | AS 2129, AS 4087 Flanges | ISO 9624, ISO 7005-1 Flanges | AWWA Flanges Standard |
| GOST Standard Flanges | API Flanges | AS/ANZ 4331.1 Flanges | Series A Flange |
| Series B Flange | SAE J518 Flanges | GB Flange | Norwegian Standard Flanges |
| ASME B16.11 – Forged Steel Fittings, Socket-Welding and Threaded | BS 3799 – Screwed and Socket-Welding for the Petroleum Industry | MSS SP-79 – Socket-Welding Reducer Inserts | MSS SP-83 – Class 3000 Steel Pipe Unions, Socket-Welding and Threaded |
| MSS SP-95 – Swage(d) Nipples and Bull Plugs | MSS SP-97 – Integrally Reinforced Forged Branch Outlet Fittings | DIN 2986 – Threaded Fittings | DIN 2999 – Pipe Threads for Fittings (British Standard Pipe Threads) |
| ISO 49 – Malleable Iron Fittings, Threaded | ISO 7/1 – Pipe Threads Where Pressure-tight Joints Are Made on the Threads | EN 10241 – Steel Threaded Pipe Fittings | JIS B2316 – Japanese standard for forged pipe fittings. |
| ANSI/ASME B16.9 – Factory-Made Wrought Steel Buttwelding Fittings | ANSI/ASME B16.28 – Wrought Steel Short Radius Elbows and Returns | ANSI/ASME B16.25 – Buttwelding Ends(beval standards) | MSS SP-43 – Wrought and fabricated Butt welding Fittings for Light Wall Applications |
| MSS SP-75 – High Test Wrought Butt welding Fittings | DIN 2616 – Butt welding Pipe Fittings: Reducers | DIN 2617 – Butt welding Pipe Fittings: Caps | DIN28011 – Dished Ends(used in pressure vessels) |
| EN10253-1 Butt-welding Pipe Fittings(Non Alloy Steels) | EN10253-2 Butt-welding Pipe Fittings(Stainless/Alloy Steels) |
Stainless Steel SMO 254 International Standards
| STANDARD | WERKSTOFF NR. | UNS | JIS | BS | KS | AFNOR | EN |
| SMO 254 | 1.4547 | S31254 | SUS 312L | – | STS 312L | Z2MCND25-20-07 | X1CrNiMoCuN20-18-7 |
SMO 254 Chemical Composition
| Grade | C | Mn | Si | P | S | Cr | Mo | Ni | Cu | N |
|---|---|---|---|---|---|---|---|---|---|---|
| SMO 254 | 0.020 max | 1.00 max | 0.80 max | 0.030 max | 0.010 max | 19.50 – 20.50 | 6.00 – 6.50 | 17.50 – 18.50 | 0.50 – 1.00 | 0.18 – 0.22 |
SMO 254 Stainless Steel Mechanical Properties
| Density | Melting Point | Tensile Strength | Yield Strength (0.2% Offset) | Elongation | Hardness (Brinell) |
|---|---|---|---|---|---|
| 8.0 g/cm³ | 1320 – 1390 °C | Psi – 100000 , MPa – 690 | Psi – 45000 , MPa – 310 | 35 % | 210 HB max |
Stainless Steel Types
Stainless Steel SMO 254 Industries & Applications
Stainless Steel SMO 254 Flange Size Chart
| Flange Weights by Pressure Class and Size | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Pipe Size | 150 # | 300 # | 600 # | 900 # | 1500 # | 2500 # | ||||||||||||
| WN | SO | BLD | WN | SO | BLD | WN | SO | BLD | WN | SO | BLD | WN | SO | BLD | WN | SO | BLD | |
| 1/2″ | 2 | 1 | 1 | 2 | 1 | 1 | 2 | 2 | 2 | SEE 1500 # WEIGHTS | 5 | 4 | 4 | 7 | 7 | 7 | ||
| 3/4″ | 2 | 2 | 2 | 3 | 3 | 3 | 4 | 3 | 3 | SEE 1500 # WEIGHTS | 6 | 5 | 6 | 8 | 8 | 8 | ||
| 1″ | 3 | 2 | 2 | 4 | 3 | 3 | 4 | 4 | 4 | SEE 1500 # WEIGHTS | 9 | 8 | 8 | 12 | 11 | 11 | ||
| 1 1/2″ | 4 | 3 | 3 | 7 | 6 | 6 | 8 | 7 | 8 | SEE 1500 # WEIGHTS | 13 | 12 | 13 | 25 | 22 | 23 | ||
| 2″ | 6 | 5 | 5 | 9 | 7 | 8 | 12 | 9 | 10 | SEE 1500 # WEIGHTS | 25 | 25 | 25 | 42 | 37 | 39 | ||
| 2 1/2″ | 8 | 7 | 7 | 12 | 10 | 12 | 18 | 13 | 15 | SEE 1500 # WEIGHTS | 36 | 36 | 35 | 52 | 55 | 56 | ||
| 3″ | 10 | 8 | 9 | 15 | 13 | 16 | 23 | 16 | 20 | 31 | 26 | 29 | 48 | 48 | 48 | 94 | 83 | 86 |
| 4″ | 15 | 13 | 17 | 25 | 22 | 27 | 42 | 37 | 41 | 53 | 53 | 54 | 73 | 73 | 73 | 145 | 125 | 130 |
| 5″ | 19 | 15 | 20 | 32 | 28 | 35 | 68 | 63 | 68 | 86 | 83 | 87 | 130 | 130 | 140 | 245 | 210 | 225 |
| 6″ | 24 | 19 | 26 | 42 | 39 | 50 | 81 | 80 | 86 | 110 | 110 | 115 | 165 | 165 | 160 | 380 | 325 | 345 |
| 8″ | 39 | 30 | 45 | 67 | 58 | 81 | 120 | 115 | 140 | 175 | 170 | 200 | 275 | 260 | 300 | 580 | 485 | 530 |
| 10″ | 52 | 43 | 70 | 91 | 81 | 124 | 190 | 170 | 230 | 260 | 245 | 290 | 455 | 435 | 510 | 1075 | 930 | 1025 |
| 12″ | 80 | 64 | 110 | 140 | 115 | 185 | 225 | 200 | 295 | 325 | 325 | 415 | 690 | 580 | 690 | 1525 | 1100 | 1300 |
| 14″ | 110 | 90 | 140 | 180 | 165 | 250 | 280 | 230 | 355 | 400 | 400 | 520 | 940 | NA | 975 | NA | NA | NA |
| 16″ | 140 | 98 | 180 | 250 | 190 | 295 | 390 | 330 | 495 | 495 | 425 | 600 | 1250 | NA | 1300 | NA | NA | NA |
| 18″ | 150 | 130 | 220 | 320 | 250 | 395 | 475 | 400 | 630 | 680 | 600 | 850 | 1625 | NA | 1750 | NA | NA | NA |
| 20″ | 180 | 165 | 285 | 400 | 315 | 505 | 590 | 510 | 810 | 830 | 730 | 1075 | 2050 | NA | 2225 | NA | NA | NA |
| 22″ | 225 | 185 | 355 | 465 | 370 | 640 | 720 | 590 | 1000 | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| 24″ | 260 | 220 | 430 | 580 | 475 | 790 | 830 | 730 | 1250 | 1500 | 1400 | 2025 | 3325 | NA | 3625 | NA | NA | NA |
SMO 254 Buttweld Fittings Dimensions
| NOMINAL PIPE SIZE | ALL FITTINGS | ALL FITTINGS | ALL FITTINGS | ELBOWS AND TEES | 180 DEG RETURN BENDS | 180 DEG RETURN BENDS | 180 DEG RETURN BENDS | REDUCERS | CAPS |
|---|---|---|---|---|---|---|---|---|---|
| NPS | O.D. at Bevel (1), (2) | I.D. at End (1), (3), (4) |
Wall Thickness (3) | Centre-to-End Dimension A,B,C,M | Centre-to-Centre O | Back-to-Face K | Alignment of Ends U | Overall Length H | Overall Length E |
| ½ to 2½ | 0.06 -0.03 |
0.03 | Not less than 87.5% of nominal thickness | 0.06 | 0.25 | 0.25 | 0.03 | 0.06 | 0.12 |
| 3 to 3 ½ | 0.06 | 0.06 | Not less than 87.5% of nominal thickness | 0.06 | 0.25 | 0.25 | 0.03 | 0.06 | 0.12 |
| 4 | 0.06 | 0.06 | Not less than 87.5% of nominal thickness | 0.06 | 0.25 | 0.25 | 0.03 | 0.06 | 0.12 |
| 5 to 8 | 0.09 -0.06 |
0.06 | Not less than 87.5% of nominal thickness | 0.06 | 0.25 | 0.25 | 0.03 | 0.06 | 0.25 |
| 10 to 18 | 0.16 -0.12 |
0.12 | Not less than 87.5% of nominal thickness | 0.09 | 0.38 | 0.25 | 0.06 | 0.09 | 0.25 |
| 20 to 24 | 0.25 -0.19 |
0.19 | Not less than 87.5% of nominal thickness | 0.09 | 0.38 | 0.25 | 0.06 | 0.09 | 0.25 |
| 26 to 30 | 0.25 -0.19 |
0.19 | Not less than 87.5% of nominal thickness | 0.12 | … | … | … | 0.19 | 0.38 |
| 32 to 48 | 0.25 -0.19 |
0.19 | Not less than 87.5% of nominal thickness | 0.19 | … | … | … | 0.19 | 0.38 |
SMO 254 Forged Fittings Dimensions
| Size | OD | WT | SR 90 Deg Elbows Centre – Face A | Weight | LR 90 Deg Elbows Centre – Face A | Weight | SR 45 Deg Elbows Centre – Face B | Weight | ||
|---|---|---|---|---|---|---|---|---|---|---|
| mm | inch. | mm | mm | SCH | mm | kg | mm | kg | mm | kg |
| 500 | 20″ | 508 | 9.52 | STD | 508 | 93.5 | 762 | 140 | 318 | 85 |
| 12.7 | X.S | 508 | 124 | 762 | 186 | 318 | 112.5 | |||
| 450 | 18″ | 457 | 9.52 | STD | 457 | 75.6 | 686 | 113 | 286 | 56.5 |
| 12.7 | X.S | 457 | 100 | 686 | 150 | 286 | 75 | |||
| 400 | 16″ | 406.4 | 9.52 | STD | 406 | 59.5 | 610 | 89.3 | 254 | 45 |
| 12.7 | X.S | 406 | 78.7 | 610 | 118 | 254 | 59 | |||
| 350 | 14″ | 355.6 | 9.52 | STD | 356 | 45.4 | 533 | 68.1 | 222 | 34.1 |
| 12.7 | X.S | 356 | 60 | 533 | 90 | 222 | 45 | |||
| 300 | 12″ | 323.9 | 9.52 | STD | 305 | 35.4 | 457 | 53.1 | 190 | 26.6 |
| 12.7 | X.S | 305 | 46.7 | 457 | 70 | 190 | 35 | |||
| 250 | 10″ | 273.9 | 9.27 | STD | 254 | 24.1 | 381 | 36.1 | 159 | 18.1 |
| 12.7 | X.S | 254 | 32.5 | 381 | 48.8 | 159 | 24.4 | |||
| 200 | 8″ | 219.1 | 8.18 | STD | 203 | 13.6 | 305 | 20.4 | 127 | 10.2 |
| 12.7 | X.S | 203 | 20.9 | 305 | 30.9 | 127 | 15.5 | |||
| 150 | 6″ | 168.3 | 7.11 | STD | 152.4 | 6.8 | 229 | 10.1 | 95.2 | 5.1 |
| 10.97 | X.S | 152.4 | 10.2 | 229 | 15.3 | 95.2 | 7.7 | |||
| 125 | 5″ | 141.3 | 6.65 | STD | 127 | 4.8 | 190 | 6.8 | 79.4 | 3.4 |
| 9.5 | X.S | 127 | 6.5 | 190 | 10 | 79.4 | 5 | |||
| 100 | 4″ | 114.3 | 62 | STD | 101.6 | 2.8 | 152.4 | 4.2 | 63.5 | 2.1 |
| 8.56 | X.S | 101.6 | 3.9 | 152.4 | 5.7 | 63.5 | 2.9 | |||
| 80 | 3″ | 88.9 | 5.49 | STD | 76.2 | 1.45 | 114.3 | 2.18 | 50.8 | 1.1 |
| 7.62 | X.S | 76.2 | 1.95 | 114.3 | 2.86 | 50.8 | 1.45 | |||
| 65 | 21/2″ | 73 | 5.16 | STD | 63.5 | 0.95 | 95.2 | 1.46 | 44.4 | 0.73 |
| 71 | X.S | 63.5 | 1.27 | 95.2 | 1.82 | 44.4 | 0.91 | |||
| 50 | 2″ | 60.3 | 3.91 | STD | 50.8 | 0.5 | 76.2 | 0.72 | 34.9 | 0.36 |
| 5.54 | X.S | 50.8 | 0.68 | 76.2 | 1 | 34.9 | 0.5 | |||
| 40 | 11/2″ | 48.3 | 3.68 | STD | 38.1 | 0.26 | 57.1 | 0.4 | 28.6 | 0.2 |
| 58 | X.S | 38.1 | 0.35 | 57.1 | 0.5 | 28.6 | 0.25 | |||
| 32 | 11/4″ | 42.2 | 3.56 | STD | 31.75 | 0.18 | 47.6 | 0.28 | 25.4 | 0.14 |
| 4.85 | X.S | 31.75 | 0.24 | 47.6 | 0.39 | 25.4 | 0.2 | |||
| 25 | 1″ | 33.4 | 3.38 | STD | 25.4 | 0.11 | 38.1 | 0.15 | 22.2 | 09 |
| 4.55 | X.S | 25.4 | 0.14 | 38.1 | 0.19 | 22.2 | 0.11 | |||
| 20 | 3/4″ | 26.7 | 2.87 | STD | – | – | 28.6 | 08 | 11.1 | 04 |
| 3.91 | X.S | – | – | 28.6 | 0.11 | 11.1 | 05 | |||
| 15 | 1/2″ | 21.3 | 2.78 | STD | – | – | 38.1 | 08 | 15.9 | 04 |
| 3.73 | X.S | – | – | 38.1 | 0.10 | 15.9 | 05 | |||
Major Industrial Stainless Steel SMO 254 Fittings & Flanges Export Countries
United Arab Emirates (UAE), Jordan, Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, United States of America (USA), Singapore, Malaysia, Azerbaijan, Armenia, Georgia, Egypt, Algeria, Nigeria, South Africa, Kenya, Morocco, Ethiopia, Ghana, Tanzania, Sudan, Uganda, Angola.