The most common materials for pipe flanges (forged grades) are: ASTM A105 (carbon steel high temperature to match A53/A106/API 5L pipes), A350 Grades LF1/2/3 (carbon steel low temperature to match A333 pipes), A694 Grades F42 to F80 (high yield carbon steel to match API 5L pipe grades), ASTM A182 Grades F5 to F91 (alloy steel flanges to match A335 pipes), A182 Grade F304/316 (stainless steel flanges to match A312 SS pipes), A182 Gr. F44/F51/F53/F55 (duplex and super duplex to match A790/A928 pipes) and various nickel alloy grades (Inconel, Incoloy, Hastelloy, Monel).
CARBON STEEL FLANGES
The chemical composition and the mechanical properties of the three main carbon steel flanges material grades:
- ASTM A105 (high-temperature carbon steel) to match A53, A106, API 5L carbon steel pipes
- ASTM A350 LF1, LF2, LF3 (low-temperature carbon steel) to match ASTM A333 pipes
- ASTM A694 F42, F52, F60, F65 (high-yield carbon steel to match API 5L X42, X52, X60, and X65 steel pipes
CHEMICAL COMPOSITION ASTM A105, A350, A694
ASTM A105 (High-temperature carbon steel flange material)
C | Mn | P | S | Si | Cu | Ni | Cr | Mo | V | |
A105 | – | 0.60 | – | – | 0.10 | – | – | – | ||
0.35 | 1.05 | 0.035 | 0.040 | 0.35 | 0.40 | 0.40 | 0.30 | 0.12 | 0.08 |
ASTM A350 (Low-Temperature carbon steel flange material)
C% | Mn% | Si% | S% | P% | Cr% | Ni% | |
A350 LF1 | 0.30 max | 0.6/1.35 | .15/.30 | .040 max | .035 max | 0.30 max | 0.40 max |
A350 LF2 | 0.30 max | 0.6/1.35 | .15/.30 | .040 max | .035 max | 0.30 max | 0.40 max |
A350 LF3 | 0.20 max | 0.9 | .20/.35 | .040 max | .035 max | 0.30 max | 3.3/3.7 |
C | Mn | P | S | Si | |
ASTM A694 F42 | 0.26-0.265 | 1.60-1.64 | 0.025-0.030 | 0.025-0.030 | 0.15-0.35 |
ASTM A694 F52 | 0.26-0.265 | 1.60-1.64 | 0.025-0.030 | 0.025-0.030 | 0.15-0.35 |
ASTM A694 F60 | 0.26-0.265 | 1.60-1.64 | 0.025-0.030 | 0.025-0.030 | 0.15-0.35 |
ASTM A694 F65 | 0.26-0.265 | 1.60-1.64 | 0.025-0.030 | 0.025-0.030 | 0.15-0.35 |
MECHANICAL PROPERTIES A105, A350, A694
ASTM A105 (High-temperature carbon steel flange material)
Property | ASTM A105 | ASTM A350-LF2 |
Tensile Strength Min, psi | 70,000 | 70,000-95,000 |
Tensile Strength Min, N/mm² | 485 | 485-655 |
Yield Strength Min, psi | 36,000 | 36,000 |
Yield Strength Min, N/mm² | 250 | 250 |
Elongation (%) | 22 | 22 |
Reduction of Area (%) | 30 | 30 |
Hardness, maximum | 187 | 15/12 ft-lbs |
CVN at -50℉ | 20/16 joules |
ASTM A694 (High-yield carbon steel flanges)
ASTM A694 Flange Material Grade | Min Yield Strength (0.2 % Offset), in ksi [MPa] | MinTensile Strength | Elongation in 2 in. or 50 mm, min % |
in ksi [MPa] | |||
A694 F42 | 42 [290] | 60 [415] | 20 |
A694 F46 | 46 [315] | 60 [415] | 20 |
A694 F48 | 48 [330] | 62 [425] | 20 |
A694 F50 | 50 [345] | 64 [440] | 20 |
A694 F52 | 52 [360] | 66 [455] | 20 |
A694 F56 | 56 [385] | 68 [470] | 20 |
A694 F60 | 60 [415] | 75 [515] | 20 |
A694 F65 | 65 [450] | 77 [530] | 20 |
A694 F70 | 70 [485] | 82 [565] | 18 |
ALLOY STEEL FLANGES
Alloy flange materials (chrome-moly) have higher chrome and molybdenum content than carbon steel flanges. Alloy steel flange materials suit high temperature and high-pressure applications and improved resistance to corrosion when compared to regular carbon steel flanges grades.

ASTM A182 alloy flanges are extremely ductile, strong and tough and easy to weld and offer oxidation and scaling resistance. These grades match with ASTM A335 alloy steel pipes.
CHEMICAL COMPOSITION ASTM A182 F5, F9, F11, F22
ELEMENT & PROPERTIES | LOW ALLOY STEEL | MEDIUM ALLOY STEEL | ||
---|---|---|---|---|
F11 CL2 | F22 CL3 | F5 | F9 | |
CARBON | 0.10-0.20 | 0.05-0.15 | 0.15 MAX | 0.15 MAX |
MANGANESE | 0.30-0.80 | 0.30-0.60 | 0.30-0.60 | 0.30-0.60 |
PHOSPHORUS MAX | 0.040 | 0.040 | 0.03 | 0.030 |
SULFUR MAX | 0.040 | 0.040 | 0.03 | 0.030 |
SILICON | 0.50-1.00 | 0.50 MAX | 0.50 MAX | 0.50-1.00 |
NICKEL MAX | – | – | 0.50 | – |
CHROMIUM | 1.00-1.50 | 2.00-2.50 | 4.00-6.00 | 8.0-10.0 |
MOLYBDENUM | 0.44-0.65 | 0.87-1.13 | 0.44-0.65 | 0.90-1.10 |
OPPER MA | – | – | – | – |
COLUMBIUM MAX | – | – | – | – |
VANADIUM MAX | – | – | – | – |
MECHANICAL PROPERTIES A182
ELEMENT & PROPERTIES | LOW ALLOY STEEL | MEDIUM ALLOY STEEL | ||
---|---|---|---|---|
F11 CL2 | F22 CL3 | F5 | F9 | |
TENSILE STRENGTH PSI (MPA) | 70,000 (485) | 75,000 (515) | 70,000 (485) | 85,000 (585) |
YIELD STRENGTH PSI MIN | 40,000 (275) | 45,000 (310) | 40,000 (275) | 55,000 (380) |
ELONGATION 2” % MIN | 20 | 20 | 20 | 20 |
REDUCTION AREA % MIN | 30 | 30 | 35 | 40 |
HARDNESS (HB) MAX* | 143 ~ 207 | 156 ~ 207 | 143 ~ 217 | 179 ~ 217 |
Recommended service for alloy steel flange material grades ASTM A182:
ASTM A182 ALLOY STEEL FLANGE | TRADE DESIGNATION | RECOMMENDED SERVICE |
A182 F1 | C-1/2 Mo Low Alloy Steel | Non-corrosive applications Including water, oil, and gases at temperatures between -29 ~ 593ºC* (Not prolonged use > 470ºC). |
A182 F2 | 0.75% Ni; Mo; 0.75% Cr Low Alloy Steel | Non-corrosive applications including water, oil, and gases at temperatures F2:-29ºC ~ 538ºC, WC5: -29ºC ~ 575ºC |
A182 F11 | 1 1/4% Chrome; 1/2% Moly Low Alloy Steel | Non-corrosive applications including water, oil, and gases at temperatures between -30ºC (-20ºF) and +593ºC (+1100ºF). |
A182 F22 | 2 1/4% Chrome Low Alloy Steel | Non-corrosive applications including water, oil, and gases at temperatures between -30ºC (-20ºF) and +593ºC (+1100ºF). |
A182 F5/F5a | 5% Chrome; 1/2% Moly, Medium Alloy Steel | Mild corrosive or erosive applications as well as non-corrosive applications at temperatures between -30ºC (-20ºF) and +650ºC (+1200ºF). |
A182 F9 | 9% Chrome; 1% Moly, Medium Alloy Steel | Mild corrosive or erosive applications as well as non-corrosive applications at temperatures between -30ºC (-20ºF) and +650ºC (+1200ºF). |
A182 F91 | 9% Chrome; 1% Moly; V-N, Medium Alloy Steel | Mild corrosive or erosive applications as well as non-corrosive applications at temperatures between -30ºC (-20ºF) and +650ºC (+1200ºF). |
STAINLESS STEEL FLANGES
The key elements that differentiate stainless steel materials for flanges, compared to other grades, are the Nickel (Ni), Chrome (Cr), and Molybdenum content (Mo). The price for these metals fluctuates daily on the London Metal Exchange (Nickel, Moly) and on the ferroalloy market (ferrochrome).
- LME price for Nickel (USD per tonne)
- LME price for Molybdenum (USD per tonne)
- LME price for Copper (USD per tonne)
- Ferrochrome market price (USD per kg.)

CHEMICAL COMPOSITION ASTM A182 F304/F316/F321
ASTM A182 Stainless Steel Flanges Materials Composition, % | |||||||||||
ASTM A182 GRADE | C | Mn | P | S | Si | Ni | Cr | Mo | Nb | Ti | Others |
---|---|---|---|---|---|---|---|---|---|---|---|
F304(1) | 0.08 | 2.0 | 0.045 | 0.030 | 1.0 | 8.0-11.0 | 18.0-20.0 | ||||
F304H | 0.04-0.10 | 2.0 | 0.045 | 0.030 | 1.0 | 8.0-11.0 | 18.0-20.0 | ||||
F304L(1) | 0.030 | 2.0 | 0.045 | 0.030 | 1.0 | 8.0-13.0 | 18.0-20.0 | ||||
F304N(2) | 0.08 | 2.0 | 0.045 | 0.030 | 1.0 | 8.0-10.5 | 18.0-20.0 | ||||
F304LN(2) | 0.030 | 2.0 | 0.045 | 0.030 | 1.0 | 8.0-10.5 | 18.0-20.0 | ||||
F309H | 0.04-0.10 | 2.0 | 0.045 | 0.030 | 1.0 | 12.0-15.0 | 22.0-24.0 | ||||
F310 | 0.25 | 2.0 | 0.045 | 0.030 | 1.0 | 19.0-22.0 | 24.0-26.0 | ||||
F310H | 0.04-0.10 | 2.0 | 0.045 | 0.030 | 1.0 | 19.0-22.0 | 24.0-26.0 | ||||
F310MoLN | 0.030 | 2.0 | 0.030 | 0.015 | 0.40 | 21.0-23.0 | 24.0-26.0 | 2.0-3.0 | N 0.10-0.16 | ||
F316 | 0.08 | 2.0 | 0.045 | 0.030 | 1.0 | 10.0-14.0 | 16.0-18.0 | 2.0-3.0 | |||
F316H | 0.04-0.10 | 2.0 | 0.045 | 0.030 | 1.0 | 10.0-14.0 | 16.0-18.0 | 2.0-3.0 | |||
F316L(1) | 0.030 | 2.0 | 0.045 | 0.030 | 1.0 | 10.0-15.0 | 16.0-18.0 | 2.0-3.0 | |||
F316N(2) | 0.08 | 2.0 | 0.045 | 0.030 | 1.0 | 11.0-14.0 | 16.0-18.0 | 2.0-3.0 | |||
F316LN(2) | 0.030 | 2.0 | 0.045 | 0.030 | 1.0 | 11.0-14.0 | 16.0-18.0 | 2.0-3.0 | |||
F316Ti | 0.08 | 2.0 | 0.045 | 0.030 | 1.0 | 10.0-14.0 | 16.0-18.0 | 2.0-3.0 | (3) | N 0.10 max | |
F317 | 0.08 | 2.0 | 0.045 | 0.030 | 1.0 | 11.0-15.0 | 18.0-20.0 | 3.0-4.0 | |||
F317L | 0.030 | 2.0 | 0.045 | 0.030 | 1.0 | 11.0-15.0 | 18.0-20.0 | 3.0-4.0 | |||
F321 | 0.08 | 2.0 | 0.045 | 0.030 | 1.0 | 9.0-12.0 | 17.0-19.0 | (4) | |||
F321H | 0.04-0.10 | 2.0 | 0.045 | 0.030 | 1.0 | 9.0-12.0 | 17.0-19.0 | (5) | |||
F347 | 0.08 | 2.0 | 0.045 | 0.030 | 1.0 | 9.0-13.0 | 17.0-20.0 | (6) | |||
F347H | 0.04-0.10 | 2.0 | 0.045 | 0.030 | 1.0 | 9.0-13.0 | 17.0-20.0 | (7) | |||
F348 | 0.08 | 2.0 | 0.045 | 0.030 | 1.0 | 9.0-13.0 | 17.0-20.0 | (6) | Co 0.20 Ta 0.10 |
||
F348H | 0.04-0.10 | 2.0 | 0.045 | 0.030 | 1.0 | 9.0-13.0 | 17.0-20.0 | (7) | Co 0.20 Ta 0.10 |
Notes:
- Grades F304, F304L, F316, and F316L shall have a maximum Nitrogen of 0.10%.
- Grades F304N, F316N, F304LN, and F316LN shall have a Nitrogen of 0.10 to 0.16%.
- Grade F316Ti shall have a Titanium content five times above the Carbon plus Nitrogen and not more than 0.70%.
- Grade F321 shall have a Titanium content five times above the Carbon and not more than 0.70%.
- Grade F321H shall have a Titanium content four times above the Carbon and not more than 0.70%.
- Grades F347 and F348 shall have a Niobium content ten times above the Carbon and not more than 1.10%.
- Grades F347H and F348H shall have a Niobium content above than eight times the Carbon and not more than 1.10%.
MECHANICAL PROPERTIES A182 F304/F316/F321
ASTM A182 Grade | Minimum Tensile Strength in MPa |
Minimum Yield point in Mpa |
Minimum Elongation in % |
Minimum Reduction of in min, % |
ASTM A182 F304 | 515 | 205 | 30 | 50 |
ASTM A182 F304L | 485 | 170 | 30 | 50 |
ASTM A182 F316 | 515 | 205 | 30 | 50 |
ASTM A182 F316L | 485 | 170 | 30 | 50 |
ASTM A182 F321 | 515 | 205 | 30 | 50 |
Recommended service for stainless steel flange materials:
MATERIAL | MATERIAL GROUP | RECOMMENDED SERVICE |
---|---|---|
A182-F304 | 18% Cr, 8% Ni Stainless Steel | Corrosive services and atmospheres from -450°F to 1000°F (-268°C to 537°C) |
A182-F316 | 18% Cr, 8% Ni, 2% Mo Stainless Steel | High resistance to corrosion from -450°F to 1000°F (-268°C to 537°C). |
ASTM vs. EN STAINLESS STEEL FLANGE MATERIALS
Flanges Material Grades: Comparison European and American Standards | ||
---|---|---|
Material number | EN | ASTM |
Stainless Steel Flange Materials | ||
1.4541 X 6 CrNiTi 18 10 | X6CrNiTi18-10 | A 182 Grade F321 |
1.4571 X 6 CrNiMoTi 17 12 2 | X6CrNiMoTi17-12-2 | A 182 Grade F316Ti |
1.4301 X 5 CrNi 18 10 | X5CrNi18-10 | A 182 Grade F304 |
1.4306 X 2 CrNi 19 11 | – | A 182 Grade F304L |
1.4307 – | X2CrNi18-9 | A 182 Grade F304L |
1.4401 X 5 CrNiMo 17 12 2 | X5CrNiMo17-12-2 | A 182 Grade F316 |
1.4404 X 2 CrNiMo 17 13 2 | X2CrNiMo17-12-2 | A 182 Grade F316L |
1.4462 X 2 CrNiMoN 22 5 3 | X2CrNiMoN22-5-3 | A 182 Grade F51 (Duplex) |
1.4529 X 1 NiCrMoCuN 25 20 6 | X1NiCrMoCuN25-20-7 | UNS N 08926 |
1.4539 X 1 NiCrMoCuN 25 20 5 | X1NiCrMoCu25-20-5 | A 182 Grade F904L |
1.4547 – | X1CrNiMoCuN20-18-7 | UNS S 3125 |
DUPLEX FLANGES
Duplex steel (ASTM A182 2205) is an extremely corrosion resistant, work hardenable stainless steel, whose microstructure consists of a mixture of austenite and ferrite phases.

Due to this particular chemical and physical composition, duplex stainless steel UNS S31803 features the properties characteristic of both types of stainless steel materials (ferritic and austenitic).
Generally speaking, duplex stainless steel is way tougher than ferritic stainless steels, has a superior strength than austenitic steels (series 300 and 400) and has superior resistance to corrosion when compared to SS304 and SS316 (high intragranular corrosion, also in chloride and sulfide environments).
Whilst austenitic stainless steels are non-magnetic, duplex stainless steel shows magnetic properties.
Duplex and super duplex flanges match with ASTM A790 seamless pipes (or A928 welded duplex pipes).
CHEMICAL COMPOSITION ASTM A182 DUPLEX AND SUPER DUPLEX
% |
Duplex 2205 |
Super Duplex |
C |
0-0.03 |
0.03 max |
Mn |
2.0 |
1.5 |
Si |
1.0 |
0.8 |
P |
0-0.03 |
0.035 |
S |
0-0.02 |
0.02 |
Cr |
21-23 |
24-26 |
Mo |
2.5-3.5 |
3.0-5.0 |
Ni |
4.5-6.5 |
5.5-8.0 |
N |
0.08-0.2 |
0.2-0.35 |
Cu |
– |
0.5-3.0 |
The most widely used grade for Duplex flange is 2205, due to its superior resistance to corrosion and mechanical strength.
The designation “2205” is related to the chemical composition of this material, which features 22% of chromium and 5% of nickel.
Super Duplex flange show an even superior strength and a higher corrosion resistance than standard duplex steel (and austenitic grades, of course).
The main difference between a duplex and a super duplex grade is the addition of copper to the alloy (in addition to increased amounts of Chromium, Moly, and Nickel).
The addition of copper gives Super Duplex Stainless Steel an improved resistance to hot chlorides and strong reducing acids, like sulphuric acid, compared to a standard Duplex grade.
Whilst UNS S31803, UNS 32205 (duplex) and UNS S32750, UNS S32760 are standard designations, most manufacturers of superalloys attribute proprietary names to these steels (example UR52N+ is a Usinor/Arcelor Super Duplex steel, Ferralium, Zeron, Sandvik SAF 2205 22Cr, etc).
MECHANICAL PROPERTIES A182 DUPLEX AND SUPER DUPLEX
Mechanical Properties |
Duplex 2205 |
Super Duplex |
Tensile Strength (in MPa) |
620 |
770 |
Proof Stress 0.2% (in MPa) |
450 |
550 |
A5 Elongation (in %) |
25 |
25 |
Physical Attribute |
Duplex 2205 |
Super Duplex |
Density (g.cm3) |
7.805 |
7.810 |
Modulus of Elasticity (GPa) |
200 |
205 |
Electrical Resistivity (Ω.m) |
0.085×10-6 |
0.085×10-6 |
Thermal Conductivity (W/m.K) |
19 at 100°C |
17 at 100°C |
Thermal Expansion (m/m.K) |
13.7×10-6 to 100°C |
13.5×10-6 to 200°C |
The significant addition of Chromium in Duplex Steel grades, that protects the alloy against corrosion, is a source of steel embrittlement at temperatures over about 300°C. However, at lower temperatures duplex steels show better ductility properties than ferritic and martensitic stainless steels (they can easily be used at a temperature below -50 C°).
NICKEL ALLOY FLANGES
ASTM SPECIFICATIONS FOR NICKEL ALLOY FLANGES
ASTM B160 | Nickel 200 Flange |
ASTM B166 | Inconel 600 Flange |
ASTM B564 | Inconel 625 Flange |
ASTM B425 | Incoloy 800 Flange |
ASTM B564 | Incoloy 825 Flange |
ASTM B564 | Monel K400 Flange |
ASTM B564 | Hastelloy C276 Flange |
CHEMICAL COMPOSITION NICKEL-ALLOY FLANGES
Superalloy Grade | UNS Equivalent | Alloy Composition | |||||||||
C | Mn | S | Si | Cr | Ni | Mo | Cu | Ti | Fe | ||
Nickel 200 | N02200 | 0.08 | 0.18 | 0.005 | 0.18 | … | 99.5(a) | … | 0.13 | … | 0.2 |
Nickel 201 | N02201 | 0.01 | 0.18 | 0.005 | 0.18 | … | 99.6(a) | … | 0.13 | … | 0.2 |
Monel 400 | N04400 | 0.15 | 1 | 0.012 | 0.25 | … | 66.5(a) | … | 31.5 | … | 1.25 |
Monel K-500 | N05500 | 0.13 | 0.75 | 0.005 | 0.25 | … | 66.5(a) | … | 29.5 | 0.6 | 1 |
Hastelloy B | N10665 | 0.05 max | 1 | … | 1 | 1 | 61 | 28 | … | … | 5 |
Hastelloy D | – | 0.12 | 0.9 | … | 9.25 | 1 | 82 | … | 3 | … | 2 |
Inconel 600 | N06600 | 0.08 | 0.5 | 0.008 | 0.25 | 15.5 | 76.0(a) | … | 0.25 | … | 8 |
Inconel 800 | N08800 | 0.05 | 0.75 | 0.008 | 0.5 | 21 | 32.5 | … | 0.38 | 0.38 | 46 |
Hastelloy C-276 | N10276 | 0.01 | 0.5 | 0.02 | 0.03 | 15.5 | 57 | 16 | … | … | 5.5 |
Inconel 625 | N06025 | 0.05 | 0.25 | 0.008 | 0.25 | 21.5 | 61.0(a) | 9 | … | 0.2 | 2.5 |
Incoloy 825 | N08825 | 0.03 | 0.5 | 0.015 | 0.25 | 21.5 | 42 | 3 | 2.25 | 0.9 | 30 |
Hastelloy G | N06030 | 0.03 | 1.5 | 0.02 | 0.5 | 22.25 | 44 | 6.5 | 2 | … | 19.5 |
20Cb-3 | N08020 | 0.04 | 1 | 0.02 | 0.5 | 20 | 34 | 2.5 | 3.5 | … | … |
MECHANICAL PROPERTIES NICKEL-ALLOY FLANGES
Superalloy grade | UNS Equivalent | Yield Strength (in ksi) |
Tensile Strength (in ksi) | Elongation % | Rockwell | Brinell |
Nickel 200 | N02200 | 15 | 55 | 35 | – | 90-120 |
Nickel 201 | N02201 | 12 | 50 | 35 | – | 90-120 |
Monel 400 | N04400 | 25 | 70 | 35 | – | 110-149 |
Monel K-500 | N05500 | 100 | 140 | 17 | – | 265-346 |
Hastelloy B-2 | N10665 | 51 | 110 | 40 | C22 | – |
Hastelloy D-205 | – | 49 | 114 | 57 | C30-39 | – |
Inconel 600 | N06600 | 30 | 80 | 35 | – | 120-170 |
Inconel 800 | N08800 | 30 | 75 | 30 | – | 120-184 |
Hastelloy C-276 | N10276 | 60 | 115 | 50 | 184 | |
Inconel 625 | N06025 | 39 | 98 | 30 | – | 180 |
Incoloy 825 | N08825 | 35 | 85 | 30 | – | 120-180 |
Hastelloy G-30 | N06030 | 51 | 100 | 56 | – | – |
20Cb-3 | N08020 | 35 | 80 | 30 | B84-90 | 160 |
7 Responses
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can you please tell me equivalent material for A694 F60 (which should have almost similar is chemical composition and yield strength.)
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