ASTM A182/A182M is the standard specification by ASTM International covering forged or rolled alloy and stainless steel pipe flanges, forged fittings, and valve parts for rated piping systems. The companion specification ASME SA-182 adopts identical requirements for ASME Boiler and Pressure Vessel Code (BPVC) compliance.
HT PIPE supplies ASTM A182 / SA-182 compliant forged products across austenitic, duplex, and martensitic grades, with full Mill Test Certificates (MTC) per EN 10204 3.1.
1. Standard Scope & Designation
ASTM A182/A182M covers three categories of forged products for rated piping:
| Category |
Products |
Size Range |
Notes |
| Flanges |
Weld neck, slip-on, socket-weld, threaded, lap joint, blind |
NPS 1/8 – NPS 80 |
Per ASME B16.5 (≤NPS 24) / B16.47 (≥NPS 26) |
| Forged Fittings |
Elbows, tees, reducers, caps, couplings, laterals, crosses |
NPS 1/8 – NPS 80 |
Socket-weld and threaded per ASME B16.11 |
| Valve Parts |
Stems, bodies, bonnets, yokes for rated valve assemblies |
All sizes |
Per applicable valve specifications |
Scope Statement (ASTM A182-23): "This specification covers forged or rolled alloy and stainless steel pipe flanges, forged fittings, and valve parts for rated piping applications. The material shall be forged or rolled and heat treated as required. The requirements for finishing, marking, and testing shall be in accordance with the methods specified herein."
| Designation |
Issuing Body |
Unit System |
Latest Edition |
| ASTM A182 |
ASTM International |
Inch-Pound |
A182/A182M-23 |
| ASTM A182M |
ASTM International |
SI (Metric) |
A182/A182M-23 |
| ASME SA-182 |
ASME (BPVC Sec. II Part A) |
Both |
2023 Edition |
2. Grades Covered by ASTM A182
ASTM A182 covers over 30 grades organized into five metallurgical families:
2.1 Austenitic Stainless Steel Grades
| Grade |
UNS No. |
Alloy Type |
Typical Application |
| F304 / F304L / F304H |
S30400 / S30403 / S30409 |
18Cr-8Ni / Low C / High C |
General chemical, food, dairy processing |
| F316 / F316L / F316H |
S31600 / S31603 / S31609 |
16Cr-10Ni-2Mo |
Marine, pharma, chemical process |
| F321 / F321H |
S32100 / S32109 |
Ti-stabilized |
High-temp piping, exhaust systems |
| F347 / F347H |
S34700 / S34709 |
Nb+Ta-stabilized |
High-temp pressure vessels, aerospace |
| F310 / F310H |
S31000 / S31009 |
25Cr-20Ni heat resisting |
Furnace, radiant tube, heat exchangers |
| FXM-11 |
S21953 |
18Cr-8Ni-Mn, low Ni |
High-strength, cryogenic applications |
| FXM-27Cb |
S44627 |
27Cr-1Ni + Nb |
High-temp oxidation, sulfur-bearing media |
2.2 Super-Austenitic Stainless Steel Grades
| Grade |
UNS No. |
Alloy Type |
Typical Application |
| F44 (254 SMO) |
S31254 |
20Cr-18Ni-6Mo (6% Mo) |
Seawater, bleach plant, desalination |
| F904L |
N08904 |
20Cr-25Ni-4Mo-1.5Cu |
H₂SO₄, phosphoric acid, offshore |
2.3 Duplex & Super-Duplex Stainless Steel Grades
| Grade |
UNS No. |
PREN* |
Typical Application |
| F51 (2205 Duplex) |
S31803 / S32205 |
~35 |
Oil & gas, chemical, desalination |
| F53 (2507 Super-Duplex) |
S32750 |
~43 |
Offshore, subsea, seawater injection |
| F55 (Zeron 100) |
S32760 |
~41 |
High-chloride, sour service (NACE) |
| F60 (2205) |
S32205 |
~35 |
Enhanced duplex for higher P-T ratings |
*PREN = %Cr + 3.3×%Mo + 16×%N (Pitting Resistance Equivalent Number)
2.4 Martensitic & Ferritic Stainless Steel Grades
| Grade |
UNS No. |
Alloy Type |
Typical Application |
| F6a / F6b |
S41000 / S41008 |
13Cr martensitic |
Valve stems, pump shafts, turbine parts |
| F429 |
S42900 |
15Cr ferritic |
Hot water tanks, automotive trim |
| F430 |
S43000 |
16-18Cr ferritic |
Kitchen equipment, automotive trim |
2.5 Low-Alloy Steel Grades
| Grade |
Typical Composition |
Typical Application |
| F1 |
0.5Mo, low C |
High-temp, creep-resistant fittings |
| F5 / F5a |
5Cr-0.5Mo |
Petroleum refinery, hydrogen service |
| F9 / F91 |
9Cr-1Mo-V, P91 type |
Ultra-supercritical power boilers |
| F22 / F22a / F22b |
2.25Cr-1Mo |
Power boilers, hydrocrackers |
| F12 / F12a / F12b |
1.25Cr-0.5Mo-Si |
Steam headers, high-temp piping |
3. Chemical Composition — Key Grades (ASTM A182 Table 1)
Values are maximum unless shown as a range. "—" = not required / not applicable. Heat analysis per ASTM A182-23.
| Grade |
C% |
Mn% |
P% |
S% |
Si% |
Cr% |
Ni% |
Mo% |
N% |
Other |
| F304 |
0.08 |
2.00 |
0.045 |
0.030 |
1.00 |
18.0–20.0 |
8.0–11.0 |
— |
— |
— |
| F304L |
0.035 |
2.00 |
0.045 |
0.030 |
1.00 |
18.0–20.0 |
8.0–12.0 |
— |
— |
— |
| F304H |
0.04–0.10 |
2.00 |
0.045 |
0.030 |
1.00 |
18.0–20.0 |
8.0–11.0 |
— |
— |
— |
| F316 |
0.08 |
2.00 |
0.045 |
0.030 |
1.00 |
16.0–18.0 |
10.0–14.0 |
2.0–3.0 |
— |
— |
| F316L |
0.035 |
2.00 |
0.045 |
0.030 |
1.00 |
16.0–18.0 |
10.0–14.0 |
2.0–3.0 |
— |
— |
| F321 |
0.08 |
2.00 |
0.045 |
0.030 |
1.00 |
17.0–19.0 |
9.0–12.0 |
— |
— |
Ti: 5×C–0.70 |
| F347 |
0.08 |
2.00 |
0.045 |
0.030 |
1.00 |
17.0–19.0 |
9.0–13.0 |
— |
— |
Nb+Ta: 10×C–1.0 |
| F310 |
0.15 |
2.00 |
0.045 |
0.030 |
1.50 |
24.0–26.0 |
19.0–22.0 |
— |
— |
— |
| F44 |
0.020 |
1.00 |
0.030 |
0.010 |
0.80 |
19.5–20.5 |
17.5–18.5 |
6.0–7.0 |
0.18–0.25 |
Cu: 0.50–1.0 |
| F904L |
0.020 |
2.00 |
0.040 |
0.030 |
1.00 |
19.0–23.0 |
23.0–28.0 |
4.0–5.0 |
— |
Cu: 1.0–2.0 |
| F51 |
0.030 |
2.00 |
0.030 |
0.020 |
1.00 |
21.0–23.0 |
4.5–6.5 |
2.5–3.5 |
0.08–0.20 |
— |
| F53 |
0.030 |
1.20 |
0.035 |
0.020 |
0.80 |
24.0–26.0 |
6.0–8.0 |
3.0–5.0 |
0.20–0.30 |
— |
| F55 |
0.030 |
1.00 |
0.030 |
0.010 |
1.00 |
24.0–26.0 |
6.0–8.0 |
3.0–4.0 |
0.20–0.30 |
Cu: 0.50–1.0, W: 0.50–1.0 |
| F6a |
0.15 |
1.00 |
0.040 |
0.030 |
1.00 |
11.5–13.5 |
0.50 |
— |
— |
— |
Note: Full product analysis tolerances per ASTM A182-23. Additional grades (F9, F22, F91, etc.) and supplementary grades per the official standard.
4. Mechanical Property Requirements (ASTM A182 Table 2)
All values are minimum requirements in the heat-treated condition. Per ASTM A182/A182M-23.
| Grade |
UNS |
Tensile Strength
min MPa (ksi) |
Yield Strength 0.2%
min MPa (ksi) |
Elong.
min % |
Hardness
max |
| F304 |
S30400 |
515 (75) |
205 (30) |
30 |
92 HRB / 200 HBW |
| F304L |
S30403 |
485 (70) |
170 (25) |
30 |
92 HRB / 200 HBW |
| F304H |
S30409 |
515 (75) |
205 (30) |
30 |
92 HRB / 200 HBW |
| F316 |
S31600 |
515 (75) |
205 (30) |
30 |
95 HRB / 217 HBW |
| F316L |
S31603 |
485 (70) |
170 (25) |
30 |
95 HRB / 217 HBW |
| F316H |
S31609 |
515 (75) |
205 (30) |
30 |
95 HRB / 217 HBW |
| F321 |
S32100 |
515 (75) |
205 (30) |
30 |
95 HRB / 217 HBW |
| F347 |
S34700 |
515 (75) |
205 (30) |
30 |
95 HRB / 217 HBW |
| F310 |
S31000 |
515 (75) |
205 (30) |
30 |
95 HRB / 217 HBW |
| F44 |
S31254 |
650 (94) |
300 (43) |
35 |
90 HRB / 195 HBW |
| F904L |
N08904 |
490 (71) |
215 (31) |
35 |
90 HRB / 200 HBW |
| F51 |
S31803 |
620 (90) |
450 (65) |
25 |
31 HRC / 293 HBW |
| F53 |
S32750 |
800 (116) |
550 (80) |
15 |
32 HRC / 310 HBW |
| F55 |
S32760 |
750 (109) |
550 (80) |
25 |
31 HRC / 293 HBW |
| F6a |
S41000 |
585 (85) |
380 (55) |
20 |
— |
Note: Forgings are typically tested in the annealed or solution-annealed condition. Hardness is not required for all grades; HRC/HBW specified for duplex and martensitic grades.
5. Heat Treatment Requirements
| Grade Family |
Condition |
Heat Treatment |
Cooling |
| Austenitic SS (F304, F316, F321, F347…) |
Solution Annealed |
1040–1100°C (1900–2010°F) min |
Rapid quench — water or air |
| Super-Austenitic (F44, F904L) |
Solution Annealed |
1100–1150°C (2010–2100°F) |
Water quench required |
| Duplex (F51, F53, F55, F60) |
Solution Annealed |
1040–1100°C (1900–2010°F) |
Water quench required |
| Martensitic (F6a, F6b) |
Annealed or Hardened |
Anneal: 840–900°C; Harden: 950–1050°C |
Air cool or oil quench (hardened) |
| Ferritic (F429, F430) |
Annealed |
760–870°C (1400–1600°F) |
Air cool |
| Low-Alloy (F1, F5, F9, F22) |
Normalized + Tempered
or Quench + Tempered |
Per specific grade requirement |
Per grade; typically air or oil quench |
Note: All ASTM A182 stainless steel forgings must be supplied in the solution-annealed condition unless otherwise specified. Low-alloy grades require normalization or quenching and tempering per ASME SA-182 requirements. Heat treatment records (temperature, time, cooling method) must be documented on the MTR.
6. Testing & Inspection Requirements
| Test |
Requirement |
Reference Standard |
| Chemical Analysis (Heat) |
One per heat / melt — all elements per Table 1 |
ASTM A182 Table 1 |
| Tensile Test (Longitudinal) |
One per heat per heat treatment lot; stress-relieved if required |
ASTM A370 |
| Hardness Test |
Per lot; Brinell, Rockwell, or Vickers |
ASTM E10 / E18 / E92 |
| Intergranular Corrosion (IGC) |
For austenitic "L" grades when supplementary requirement specified |
ASTM A262 Practice A, B, or E |
| Intermetallic Phase (Duplex) |
Required for F51, F53, F55 when specified |
ASTM A923 Method B or C |
| Impact Test (Charpy) |
For low-alloy grades and when specified for stainless |
ASTM E23 |
| Hydrostatic Test |
Flanges and fittings may be tested at 1.5× design pressure (PN/Class) |
ASME B16.5 / B16.11 |
| Visual & Dimensional |
100% visual inspection; dimensional per ASME B16.5/B16.11/B16.47 |
ASME B16.5, B16.11, B16.47 |
7. Dimensional Standards for ASTM A182 Products
| Product |
Dimensional Standard |
Size / Pressure Class Range |
Face Types |
| Forged Flanges |
ASME B16.5 |
NPS 1/2 – NPS 24; Class 150–2500 |
RF, FF, RTJ, SW, THD |
| Large Diameter Flanges |
ASME B16.47 |
NPS 26 – NPS 60; Class 75–2500 |
RF, RTJ |
| Socket-Weld Fittings |
ASME B16.11 |
NPS 1/8 – NPS 4; Class 2000/3000/6000/9000 |
Socket ends |
| Threaded Fittings |
ASME B16.11 |
NPS 1/8 – NPS 4; Class 2000/3000/6000/9000 |
NPT threaded ends |
| Butt-Weld Fittings (Forged) |
ASME B16.9 / B16.28 |
NPS 1/2 – NPS 48; schedules STD/XS/XXS |
BW bevel ends |
RF = Raised Face; FF = Flat Face; RTJ = Ring Type Joint; SW = Socket Weld; THD = Threaded; BW = Butt Weld. Pressure-temperature ratings per ASME B16.5 Tables for each Class.
8. Industries & Applications
| Industry |
Recommended Grades |
Typical Components |
| Oil & Gas / Offshore |
F316L, F51, F53, F55 |
Weld neck flanges, tee fittings, piping spool joints |
| Chemical & Petrochemical |
F304, F316L, F904L, F44 |
Flanged pipe joints, valve manifolds, process piping |
| Power Generation |
F321H, F347H, F91, F22 |
High-temp boiler piping, steam header flanges |
| Desalination / Water |
F316L, F51, F53 |
Seawater intake/outfall, brine lines, heat exchangers |
| Pharmaceutical / Food |
F304L, F316L |
Hygienic piping, CIP systems, sterile process lines |
| Refinery / Hydroprocessing |
F5, F9, F22, F316L |
Charge heater flanges, reactor manways, piping |
9. ASTM A182 vs ASME SA-182 — Key Differences
| Criteria |
ASTM A182 |
ASME SA-182 |
| Issuing Body |
ASTM International |
ASME (BPVC Section II, Part A) |
| Scope |
General industrial forgings |
ASME Code pressure piping & vessels |
| Technical Requirements |
Full specification |
Identical (adopted from ASTM A182) |
| Material Traceability |
Standard MTR |
Certified MTR with heat traceability |
| Authorized Inspection |
Not required |
Required per ASME BPVC |
| Code Stamp Piping |
Not required |
Required for B31.1 / B31.3 Code piping |
Dual Certification: Most A182 forgings can be dual-certified as both ASTM A182 and ASME SA-182 without additional cost. Always verify which specification is required by the project engineer or applicable code before ordering.
10. Related Standards
| Standard |
Scope |
Relationship to A182 |
| ASME B16.5 |
Pipe Flanges & Flanged Fittings NPS 1/2 – 24 |
Dimensional standard for A182 flanges |
| ASME B16.11 |
Forged Fittings, SW & Threaded |
Dimensional standard for A182 fittings |
| ASME B16.47 |
Large Diameter Steel Flanges NPS 26+ |
Dimensional standard for large A182 flanges |
| ASTM A370 |
Mechanical Testing of Steel Products |
Tensile test method required by A182 |
| ASTM A262 |
Intergranular Corrosion Test |
Supplementary requirement for L-grades |
| ASTM A923 |
Intermetallic Phase in Duplex SS |
Required for duplex F51/F53/F55 grades |
| ASTM A403/A403M |
Wrought Austenitic SS Butt-Weld Fittings |
Companion spec for BW fittings (not forging) |
| ASME B31.3 |
Process Piping Code |
Governs allowable stress & design of A182 piping |
11. How to Order — Required Information
| No. |
Item |
Requirement / Example |
| 1 |
Specification |
ASTM A182 / ASME SA-182 |
| 2 |
Grade / UNS |
e.g., Grade F316L (UNS S31603) |
| 3 |
Product Type |
Weld neck flange / elbow / tee / reducer / cap / coupling |
| 4 |
Size / Pressure Class |
e.g., NPS 4, Class 300; or NPS 2×1, Reducing tee |
| 5 |
End Connection |
BW (bevel) / SW (socket) / THD (NPT) / WN (weld neck) |
| 6 |
Face Type / Finish |
RF (raised face), FF (flat face), RTJ (ring joint) |
| 7 |
Supplementary Tests |
A262 IGC, A923 (duplex), Charpy impact, PMI, UT |
| 8 |
Certification |
EN 10204 3.1 Certified Mill Test Report |
| 9 |
Quantity |
Pieces, sets, or weight (kg / MT) |
12. Frequently Asked Questions
Q: What is ASTM A182?
ASTM A182/A182M is the standard specification for forged or rolled alloy and stainless steel pipe flanges, forged fittings, and valve parts for rated piping. It covers weld neck, slip-on, socket-weld, threaded, and blind flanges (NPS 1/8 to NPS 80), as well as elbows, tees, reducers, and other forged fittings per ASME B16.5 and B16.11 dimensional standards.
Q: What is the difference between ASTM A182 and ASTM A403?
ASTM A182 covers forged fittings (elbows, tees, etc.) made by hot forging. ASTM A403/A403M covers wrought butt-weld fittings, which are formed from pipe or plate and have beveled ends for welding. The grade designations and chemistry are largely similar (F304 vs WP304), but the manufacturing process and dimensional standards are different.
Q: What are the mechanical properties of ASTM A182 F316L?
ASTM A182 F316L (UNS S31603): minimum tensile strength 485 MPa (70 ksi), yield strength 0.2% offset min. 170 MPa (25 ksi), elongation min. 30% in 2 inches, hardness max. 95 HRB / 217 HBW. Must be solution annealed at 1040–1100°C and rapidly cooled.
Q: Can ASTM A182 F51 duplex fittings be used in seawater?
Yes. F51 (S31803/S32205) with PREN ~35 is widely used in seawater piping and moderate chloride environments. For higher chloride concentrations (>35,000 ppm Cl⁻), F53 (S32750, PREN ~43) or F55 (S32760, PREN ~41) with their higher Cr and Mo content are preferred. All duplex grades must be solution annealed and water quenched to achieve the correct phase balance.
Q: What face types are available for ASTM A182 flanges?
ASME B16.5 flanges per A182 are available in Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ), Socket Weld (SW), and Threaded (THD/NPT) configurations. Large diameter B16.47 flanges are typically RF or RTJ. Specify the face type clearly in the purchase order to ensure correct flange facing and gasket selection.
Q: Is ASTM A182 the same as ASME SA-182?
Technically identical in chemistry and mechanical properties. ASME SA-182 is ASTM A182 adopted into ASME BPVC Section II Part A. SA-182 additionally requires Certified Material Test Reports (CMTR) with full heat traceability and authorized inspection for ASME Code-stamped pressure vessels and B31.3 process piping. Most forgings are dual-certified A182/SA-182 at no additional cost.
Request a Quote — ASTM A182 Forged Fittings & Flanges
Zhengzhou Huitong (HT Pipe) supplies ASTM A182 / SA-182 compliant forged flanges, fittings, and valve parts across all standard grades including austenitic, duplex, and low-alloy. Full EN 10204 3.1 CMTRs and competitive lead times from China.
