Stainless Steel Flanges
Corrosion-resistant Piping Solutions
Stainless steel flanges offer corrosion resistance and durability for industrial piping, ideal for chemical and food industries as of august 2025.
Corrosion-resistant Piping Solutions
Stainless steel flanges offer corrosion resistance and durability for industrial piping, ideal for chemical and food industries as of august 2025.
A stainless steel flange (SS flange) is a key piping component designed for strength, corrosion resistance, and durability across industries.
A stainless steel flange is used to connect pipes, valves, pumps, and other equipment in piping systems. Common material standards and grades include ASTM A182 Grade F304/L and F316/L, with pressure ratings from Class 150 to Class 2500.
Compared to carbon steel flanges, stainless steel flanges offer superior corrosion resistance, longer service life, and a clean, professional appearance.
Excellent performance in harsh and corrosive environments.
Suitable for high-pressure and high-temperature service.
Clean surface finish, ideal for hygienic industries.
Widely used in oil & gas, chemical, food, marine, and power industries.
| Grade | Main Feature | Applications |
|---|---|---|
| 304 | General purpose, good corrosion resistance | Water, gas, low-temp service |
| 304L | Low carbon, improved weldability | Welded piping systems |
| 316 | Superior resistance to chlorides & acids | Marine, chemical, offshore |
| 316L | Low carbon, excellent corrosion resistance | High corrosive welded environments |
| 321 | Titanium stabilized, high-temp strength | Heat exchangers, aerospace, boilers |
| Grade | C (% max) | Mn (% max) | Si (% max) | P (% max) | S (% max) | Cr (%) | Ni (%) | Mo (%) | N (% max) |
|---|---|---|---|---|---|---|---|---|---|
| 304 | 0.08 | 2.00 | 1.00 | 0.045 | 0.030 | 18.0-20.0 | 8.0-11.0 | - | 0.10 |
| 304L | 0.03 | 2.00 | 1.00 | 0.045 | 0.030 | 18.0-20.0 | 8.0-12.0 | - | 0.10 |
| 316 | 0.08 | 2.00 | 1.00 | 0.045 | 0.030 | 16.0-18.0 | 10.0-14.0 | 2.0-3.0 | 0.10 |
| 316L | 0.03 | 2.00 | 1.00 | 0.045 | 0.030 | 16.0-18.0 | 10.0-14.0 | 2.0-3.0 | 0.10 |
The low carbon content in 304L and 316L enhances weldability, while molybdenum in 316 and 316L improves resistance to pitting and crevice corrosion, making Stainless Steel Flanges ideal for harsh environments.
| Grade | Tensile Strength (min, MPa) | Yield Strength (min, MPa) | Elongation (min, %) | Hardness (max, HB) | Hardness (max, HRB) |
|---|---|---|---|---|---|
| 304 | 515 | 205 | 40 | 201 | 92 |
| 304L | 485 | 170 | 40 | 201 | 92 |
| 316 | 515 | 205 | 40 | 217 | 95 |
| 316L | 485 | 170 | 40 | 217 | 95 |
These mechanical properties make Stainless Steel Flanges suitable for applications requiring high strength and corrosion resistance, such as architectural structures, marine environments, and chemical processing.
In order to solve the cumbersome and difficult to remember stainless steel grades, improve the practicability of the brand representation, and the contrast with the international standard grades, China has formulated the "Universal Code System for Steel and Alloy Grades", such as 06Cr19Ni10, corresponding to 304. Different grades of stainless steel have different ingredients, but they all have a national standard. The standards of each country are also different.
| No | China (GB) | Japan (JIS) | American | Korea (KS) | EU (BS EN) | India (IS) | Australia (AS) | Taiwan (CNS) | ||
|---|---|---|---|---|---|---|---|---|---|---|
| Old | New (07.10) | SUS | ASTM | UNS | STS | EN | IS | AS | CNS | |
| Austenitic Stainless Steel | ||||||||||
| 1 | 1Cr17Mn6Ni5N | 12Cr17Mn6Ni5N | SUS201 | 201 | S20100 | STS201 | 1.4372 | 10Cr17Mn6Ni4N20 | 201-2 | 201 |
| 2 | 1Cr18Mn8Ni5N | 12Cr18Mn9Ni5N | SUS202 | 202 | S20200 | STS202 | 1.4373 | — | — | 202 |
| 3 | 1Cr17Ni7 | 12Cr17Ni7 | SUS301 | 301 | S30100 | STS301 | 1.4319 | 10Cr17Ni7 | 301 | 301 |
| 4 | 0Cr18Ni9 | 06Cr19Ni10 | SUS304 | 304 | S30400 | STS304 | 1.4301 | 07Cr18Ni9 | 304 | 304 |
| 5 | 00Cr19Ni10 | 022Cr19Ni10 | SUS304L | 304L | S30403 | STS304L | 1.4306 | 02Cr18Ni11 | 304L | 304L |
| 6 | 0Cr19Ni9N | 06Cr19Ni10N | SUS304N1 | 304N | S30451 | STS304N1 | 1.4315 | — | 304N1 | 304N1 |
| 7 | 0Cr19Ni10NbN | 06Cr19Ni9NbN | SUS304N2 | XM21 | S30452 | STS304N2 | — | — | 304N2 | 304N2 |
| 8 | 00Cr18Ni10N | 022Cr19Ni10N | SUS304LN | 304LN | S30453 | STS304LN | — | — | 304LN | 304LN |
| 9 | 1Cr18Ni12 | 10Cr18Ni12 | SUS305 | 305 | S30500 | STS305 | 1.4303 | — | 305 | 305 |
| 10 | 0Cr23Ni13 | 06Cr23Ni13 | SUS309S | 309S | S30908 | STS309S | 1.4833 | — | 309S | 309S |
| 11 | 0Cr25Ni20 | 06Cr25Ni20 | SUS310S | 310S | S31008 | STS310S | 1.4845 | — | 310S | 310S |
| 12 | 0Cr17Ni12Mo2 | 06Cr17Ni12Mo2 | SUS316 | 316 | S31600 | STS316 | 1.4401 | 04Cr17Ni12Mo2 | 316 | 316 |
| 13 | 0Cr18Ni12Mo3Ti | 06Cr17Ni12Mo2Ti | SUS316Ti | 316Ti | S31635 | — | 1.4571 | 04Cr17Ni12MoTi20 | 316Ti | 316Ti |
| 14 | 00Cr17Ni14Mo2 | 022Cr17Ni12Mo2 | SUS316L | 316L | S31603 | STS316L | 1.4404 | 02Cr17Ni12Mo2 | 316L | 316L |
| 15 | 0Cr17Ni12Mo2N | 06Cr17Ni12Mo2N | SUS316N | 316N | S31651 | STS316N | — | — | 316N | 316N |
| 16 | 00Cr17Ni13Mo2N | 022Cr17Ni13Mo2N | SUS316LN | 316LN | S31653 | STS316LN | 1.4429 | — | 316LN | 316LN |
| 17 | 0Cr18Ni12Mo2Cu2 | 06Cr18Ni12Mo2Cu2 | SUS316J1 | — | — | STS316J1 | — | — | 316J1 | 316J1 |
| 18 | 00Cr18Ni14Mo2Cu2 | 022Cr18Ni14Mo2Cu2 | SUS316J1L | — | — | STS316J1L | — | — | — | 316J1L |
| 19 | 0Cr19Ni13Mo3 | 06Cr19Ni13Mo3 | SUS317 | 317 | S31700 | STS317 | — | — | 317 | 317 |
| 20 | 00Cr19Ni13Mo3 | 022Cr19Ni13Mo3 | SUS317L | 317L | S31703 | STS317L | 1.4438 | — | 317L | 317L |
| 21 | 0Cr18Ni10Ti | 06Cr18Ni11Ti | SUS321 | 321 | S32100 | STS321 | 1.4541 | 04Cr18Ni10Ti20 | 321 | 321 |
| 22 | 0Cr18Ni11Nb | 06Cr18Ni11Nb | SUS347 | 347 | S34700 | STS347 | 1.4550 | 04Cr18Ni10Nb40 | 347 | 347 |
| Austenitic-Ferritic Stainless Steel (Duplex) | ||||||||||
| 23 | 0Cr26Ni5Mo2 | — | SUS329J1 | 329 | S32900 | STS329J1 | 1.4477 | — | 329J1 | 329J1 |
| 24 | 00Cr18Ni5Mo3Si2 | 022Cr19Ni5Mo3Si2N | SUS329J3L | — | S31803 | STS329J3L | 1.4462 | — | 329J3L | 329J3L |
| Ferritic Stainless Steel | ||||||||||
| 25 | 0Cr13Al | 06Cr13Al | SUS405 | 405 | S40500 | STS405 | 1.4002 | 04Cr13 | 405 | 405 |
| 26 | — | 022Cr11Ti | SUH409 | 409 | S40900 | STS409 | 1.4512 | — | 409L | 409L |
| 27 | 00Cr12 | 022Cr12 | SUS410L | — | — | STS410L | — | — | 410L | 410L |
| 28 | 1Cr17 | 10Cr17 | SUS430 | 430 | S43000 | STS430 | 1.4016 | 05Cr17 | 430 | 430 |
| 29 | 1Cr17Mo | 10Cr17Mo | SUS434 | 434 | S43400 | STS434 | 1.4113 | — | 434 | 434 |
| 30 | — | 022Cr18NbTi | — | — | S43940 | — | 1.4509 | — | 439 | 439 |
| 31 | 00Cr18Mo2 | 019Cr19Mo2NbTi | SUS444 | 444 | S44400 | STS444 | 1.4521 | — | 444 | 444 |
| Martensitic Stainless Steel | ||||||||||
| 32 | 1Cr12 | 12Cr12 | SUS403 | 403 | S40300 | STS403 | — | — | 403 | 403 |
| 33 | 1Cr13 | 12Cr13 | SUS410 | 410 | S41000 | STS410 | 1.4006 | 12Cr13 | 410 | 410 |
| 34 | 2Cr13 | 20Cr13 | SUS420J1 | 420 | S42000 | STS420J1 | 1.4021 | 20Cr13 | 420 | 420J1 |
| 35 | 3Cr13 | 30Cr13 | SUS420J2 | — | — | STS420J2 | 1.4028 | 30Cr13 | 420J2 | 420J2 |
| 36 | 7Cr17 | 68Cr17 | SUS440A | 440A | S44002 | STS440A | — | — | 440A | 440A |
There are six most commonly used flanges, also knows as ANSI Flange, ASME B16.5 Flange. However, these designs can be modified to meet the specific functions and requirements of the applications. Therefore, it’s essential to understand the pressure at the flagged joint, the required strength, and the size of pipes involved. With the correct information comes six types of flanges that an individual can choose from. These include:
Special Flanges
Additionally, the flanges can be modified to form other types, depending on application and functions.
These unique designs are made to incorporate specific needs and applications, like reducing flanges to answer to size and orifice flanges to incorporate orifice mounting.
Incoloy 825 Flange
Industries Using
The basic application of the Stainless Steel Flanges to connect pumps, pipes, valves, and other equipment, often using butt welds, to make a pipework system.
Alloy steel flanges are mainly made up of chromium...
Carbon steel flange and end flange connectors are ...