Premium SS 400 Series Fittings & Flanges – Grades 409, 410, 420, 430, 440A/B/C, 446 – Flanges & Fittings – Buttweld, Forged & Outlet Types for Structural, Automotive & Industrial Applications – NACE, PED, IBR Certified.
We are an ISO 9001:2015 certified manufacturer and global supplier of Stainless Steel 400 Series components, offering a wide range of grades such as 409, 410, 420, 430, 440A, 440B, 440C, and 446. Our portfolio includes buttweld pipe fittings, flanges, forged fittings, and olets manufactured in compliance with ASTM A403, A182, and dimensional standards like ASME B16.5, B16.9, B16.11, and MSS SP-97. These stainless steel grades are known for their excellent mechanical properties, wear resistance, and high-temperature performance, making them ideal for critical industrial environments.
The 400 Series includes ferritic (409, 430, 446) and martensitic (410, 420, 440A/B/C) stainless steels. Ferritic grades such as 409 and 430 offer good corrosion resistance, oxidation resistance, and weldability – suitable for exhaust systems, heat exchangers, and architectural use. Martensitic grades like 410, 420, and 440C provide high hardness, wear resistance, and mechanical strength – ideal for cutlery, valves, pumps, and tooling applications. We supply buttweld elbows, tees, reducers, and pipe caps, flanges (WNRF, SORF, BLRF, RTJ), forged fittings (socket weld/threaded), and olets (Weldolet, Sockolet, Threadolet) in Class 150 to 2500 and schedules SCH 10 to XXS.
Stainless Steel 400 Series is widely used in automotive exhaust systems, heat-resistant applications, petrochemical processing, industrial tooling, furnace components, kitchen equipment, and power generation. Grade 446 excels in high-temperature and oxidation-resistant service; 440C is widely chosen for knife blades and bearing parts due to its exceptional hardness; while 430 and 409 are common in fabrication and structural uses due to good formability and corrosion resistance. These grades strike a balance between performance and cost-effectiveness, making them suitable for high-volume and long-term industrial applications.
All products are manufactured with strict quality control, including mechanical testing, hardness inspection, PMI, corrosion resistance tests, and dimensional verification. We supply material with full traceability and EN 10204 3.1 / 3.2 certification, along with NACE MR0175 compliance when applicable. With ready stock and custom production facilities, we ensure fast worldwide delivery and reliable after-sales support. Whether for standard or critical use, we are your trusted source for Stainless Steel 400 Series fittings, flanges, forged fittings, and olets tailored to your application needs.
Comprehensive Range of Stainless Steel 400 Series Pipe Fittings & Flanges – Including WNRF, SORF, Blind Flanges, Buttweld Elbows, Tees, Reducers, Forged Fittings, Couplings, Unions, Bushings, Weldolet, Sockolet, Threadolet – ASME B16.5/B16.9/B16.11 Standards – Pressure Ratings 150 to 2500#.
Technical Index
Industrial Stainless Steel 409 Specifications
| Material Grade | SS 409, 410, 420, 430, 440A, 440B, 44C, 446 / 1.4512, 1.4006, 1.4021, 1.4016, 1.4102, 1.4125, 1.4749, 1.4762 / UNS S40900, S41000, S42000, S43000, S44002, S44003, S44004, S44600 |
|---|---|
| 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 430 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 410 International Standards
| Grade | UNS | Werkstoff Nr. | JIS | EN |
|---|---|---|---|---|
| SS 409 | S40900 | 1.4512 | SUS 409 | X2CrTi12 |
| SS 410 | S41000 | 1.4006 | SUS 410 | X12Cr13 |
| SS 420 | S42000 | 1.4021 | SUS 420J1 / 420J2 | X20Cr13 |
| SS 430 | S43000 | 1.4016 | SUS 430 | X6Cr17 |
| SS 440A | S44002 | 1.4102 | SUS 440A | X70Cr17 |
| SS 440B | S44003 | – | SUS 440B | X80Cr17 |
| SS 440C | S44004 | 1.4125 | SUS 440C | X105CrMo17 |
| SS 446 | S44600 | 1.4749 / 1.4762 | SUS 446 | X10CrAl13 / X18CrN28 |
Stainless Steel 420 Chemical Composition
| Grade | C (%) | Mn (%) | Si (%) | P (%) | S (%) | Cr (%) | Ni (%) | Mo (%) |
|---|---|---|---|---|---|---|---|---|
| SS 409 | 0.08 max | 1.00 max | 1.00 max | 0.045 max | 0.030 max | 10.5 – 11.75 | 0.50 max | – |
| SS 410 | 0.15 max | 1.00 max | 1.00 max | 0.040 max | 0.030 max | 11.5 – 13.5 | 0.75 max | – |
| SS 420 | 0.15 min | 1.00 max | 1.00 max | 0.040 max | 0.030 max | 12.0 – 14.0 | 0.75 max | – |
| SS 430 | 0.12 max | 1.00 max | 1.00 max | 0.040 max | 0.030 max | 16.0 – 18.0 | 0.75 max | – |
| SS 440A | 0.60 – 0.75 | 1.00 max | 1.00 max | 0.040 max | 0.030 max | 16.0 – 18.0 | 0.75 max | – |
| SS 440B | 0.75 – 0.95 | 1.00 max | 1.00 max | 0.040 max | 0.030 max | 16.0 – 18.0 | 0.75 max | – |
| SS 440C | 0.95 – 1.20 | 1.00 max | 1.00 max | 0.040 max | 0.030 max | 16.0 – 18.0 | 0.75 max | – |
| SS 446 | 0.20 max | 1.50 max | 1.00 max | 0.040 max | 0.030 max | 23.0 – 27.0 | 0.50 max | – |
Stainless Steel 446 Mechanical Properties
| Grade | Density (g/cm³) | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) | Hardness (HB) |
|---|---|---|---|---|---|
| SS 409 | 7.80 | 380 – 450 | 170 min | 20 | 170 max |
| SS 410 | 7.75 | 450 – 790 | 205 min | 20 | 183 – 223 |
| SS 420 | 7.75 | 700 – 850 | 345 min | 15 | 200 – 240 |
| SS 430 | 7.70 | 450 – 600 | 205 min | 22 | 150 – 200 |
| SS 440A | 7.75 | 740 – 900 | 450 min | 10 | 223 – 260 |
| SS 440B | 7.75 | 760 – 960 | 500 min | 8 | 240 – 280 |
| SS 440C | 7.75 | 760 – 980 | 540 min | 6 – 8 | 255 – 285 |
| SS 446 | 7.75 | 485 – 620 | 275 min | 18 | 160 – 200 |
Stainless Steel 400 Series Types
Stainless Steel 440A Industries & Applications
Stainless Steel 400 Series 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 |
SS 440B 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 |
SS 440C 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 400 Series 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.