ASTM A694 F52 Carbon Steel Flanges – A694 Gr F52 High-Yield Pipeline Flanges
ASC LLP, Mumbai, supplies ASTM A694 F52 flanges: high-yield forged carbon steel weld neck, blind and special flanges for API 5L X52 pipelines, to MSS SP-44, ASME B16.5 and B16.47. In addition, every flange comes with an EN 10204 3.1 certificate. See also our full range of carbon steel flanges.
What is ASTM A694 F52 Material?
ASTM A694 is the specification for carbon and alloy steel forgings for pipe flanges, fittings, valves and parts for high-pressure transmission service. Its grades are named after the minimum yield strength, so F52 means a 52 ksi (360 MPa) minimum yield. As a result, an F52 flange matches the strength of API 5L X52 line pipe, and it can be welded to X52 pipe without the flange becoming the weak point.
By contrast, ordinary A105 flanges have only 36 ksi (250 MPa) yield. For this reason, high-yield A694 flanges are used on oil and gas transmission lines, where the pipe wall is designed on high-strength X-grades.
A694 F52 – Quick Facts
- Specification: ASTM A694, Grade F52
- Strength: 360 MPa (52 ksi) yield / 455 MPa (66 ksi) tensile min
- Material: forged carbon (or low-alloy) steel, then heat treated
- Matching pipe: API 5L X52 (L360)
- Matching fittings: MSS SP-75 / ASTM A860 WPHY 52
- Standards: MSS SP-44, ASME B16.5, B16.47
A694 F52 Chemical Composition
| Element | ASTM A694 (all grades), % |
| Carbon (C) | 0.30 max |
| Manganese (Mn) | 1.60 max |
| Phosphorus (P) | 0.025 max |
| Sulphur (S) | 0.025 max |
| Silicon (Si) | 0.15 – 0.35 |
| Cu, Ni, Cr, Mo, V, Nb, B | To be reported |
A694 uses one chemistry for all grades, so the strength of each grade comes from the steel design and the heat treatment. However, the other elements must be reported on the certificate. In addition, pipeline buyers usually add a carbon equivalent limit (for example CE ≤ 0.43), because the flange must be field-welded to the pipe.
A694 F52 Mechanical Properties
| Property | A694 Grade F52 |
| Yield strength, min (0.2% offset) | 360 MPa (52 ksi) |
| Tensile strength, min | 455 MPa (66 ksi) |
| Elongation in 50 mm, min | 20% |
A694 itself does not require hardness or impact tests. However, most pipeline specifications add them; for example, Charpy tests at the minimum design temperature and a maximum hardness for sour service. Therefore, state any such tests on the order.
ASTM A694 Grades F42 to F70
| Grade | Yield, min (MPa) | Tensile, min (MPa) | Matching pipe |
| F42 | 290 | 415 | X42 |
| F46 | 315 | 415 | X46 |
| F48 | 330 | 425 | – |
| F50 | 345 | 440 | – |
| F52 | 360 | 455 | X52 |
| F56 | 385 | 470 | X56 |
| F60 | 415 | 515 | X60 |
| F65 | 450 | 530 | X65 |
| F70 | 485 | 565 | X70 |
In short, the flange grade is chosen to match the pipe grade; for example, F52 goes with X52 and F65 with X65. In addition, elongation is 20% for every grade except F70, which needs 18%.
A694 F52 Flange Dimensions – ASME B16.5 Class 150 & 300
| NPS | Class 150 – OD / bolt circle (in) / bolts | Class 300 – OD / bolt circle (in) / bolts |
| ½” | 3.50 / 2.38 / 4 × ½” | 3.75 / 2.62 / 4 × ½” |
| 1″ | 4.25 / 3.12 / 4 × ½” | 4.88 / 3.50 / 4 × ⅝” |
| 2″ | 6.00 / 4.75 / 4 × ⅝” | 6.50 / 5.00 / 8 × ⅝” |
| 3″ | 7.50 / 6.00 / 4 × ⅝” | 8.25 / 6.62 / 8 × ¾” |
| 4″ | 9.00 / 7.50 / 8 × ⅝” | 10.00 / 7.88 / 8 × ¾” |
| 6″ | 11.00 / 9.50 / 8 × ¾” | 12.50 / 10.62 / 12 × ¾” |
| 8″ | 13.50 / 11.75 / 8 × ¾” | 15.00 / 13.00 / 12 × ⅞” |
| 10″ | 16.00 / 14.25 / 12 × ⅞” | 17.50 / 15.25 / 16 × 1″ |
| 12″ | 19.00 / 17.00 / 12 × ⅞” | 20.50 / 17.75 / 16 × 1⅛” |
Dimensions are in inches to ASME B16.5, and bolts are shown as number × diameter. However, weld neck flanges for pipelines are bored to match the pipe wall thickness, so please state the pipe OD and wall on your enquiry. In addition, Classes 600 to 2500 and sizes above NPS 24 (B16.47 / MSS SP-44) are supplied to the same standard.
ASTM A694 F52 Flanges Specifications
| Item | Details |
| Specification | ASTM A694, Grade F52 |
| Flange types | Weld neck, blind, long weld neck, anchor and swivel flanges; also slip-on and orifice flanges |
| Dimensions | MSS SP-44, ASME B16.5, ASME B16.47 Series A / B |
| Size | NPS ½ to 60 |
| Pressure class | 150, 300, 600, 900, 1500, 2500 |
| Facing | RF, FF, RTJ |
| Bore | Matched to the pipe wall thickness, for example X52 SCH 40 / STD / XS |
| Heat treatment | Normalised, normalised and tempered, or quenched and tempered |
| Testing | Chemistry and tensile; in addition, Charpy, hardness, UT and third-party inspection on request |
| Certificate | EN 10204 3.1; also 3.2 on request |
A694 F52 Flanges – Matching Pipe, Fittings & Bolting
| Component | Matching grade |
| Line pipe | API 5L X52 (PSL1 / PSL2) |
| Buttweld fittings | MSS SP-75 / ASTM A860 WPHY 52 |
| Stud bolts / nuts | A193 B7 with A194 2H |
| Higher grades | A694 F60 / F65 with WPHY 60 / WPHY 65 |
Because pipeline systems are designed on yield strength, every part should match the X52 pipe. By contrast, for plant piping at low temperature, A350 LF2 flanges are used instead, while A216 WCB covers cast valve flanges.
A694 F52 Flange Heat Treatment & Welding
- Heat treatment: A694 flanges are normalised, normalised and tempered, or quenched and tempered, so they reach the F52 yield strength.
- Weldability: carbon content and carbon equivalent are kept low, because the flange is welded to the pipe in the field.
- Bevel: weld neck ends are bevelled to ASME B16.25, and the bore is matched to the pipe; in addition, unequal-wall transitions follow the pipeline code.
Applications of ASTM A694 F52 Flanges
| Application | Typical A694 F52 flange use |
| Oil & gas transmission | Flanged joints on X52 crude and gas lines, as well as product pipelines |
| Compressor & pump stations | Station piping and valve connections, as well as launcher and receiver traps |
| Gas distribution | City gate stations as well as metering skids |
| Gathering lines | Wellsite and field gathering systems, while sour service needs extra testing |
A694 is a carbon steel grade, so it is not chosen for corrosion resistance. Therefore, corrosive service still relies on coatings, corrosion allowance or a different material.
A694 F52 Flanges Supplier – ASC LLP, Mumbai
ASC LLP supplies ASTM A694 F52 flanges forged by approved mills, so every flange is traceable to its heat number and certificate. In addition, we supply matching WPHY fittings and stud bolts, as well as F60 and F70 flanges for higher pipe grades.
Frequently Asked Questions – ASTM A694 F52 Flanges
What is ASTM A694 F52 material?
ASTM A694 F52 is a high-yield forged carbon steel for pipeline flanges and fittings, with 360 MPa (52 ksi) minimum yield and 455 MPa (66 ksi) minimum tensile strength.
What does F52 mean in A694?
The number gives the minimum yield strength in ksi. In other words, F52 has 52 ksi (360 MPa) minimum yield, so it matches API 5L X52 pipe.
What is the chemical composition of A694 F52?
A694 allows C 0.30% max, Mn 1.60% max, P 0.025% max, S 0.025% max and Si 0.15–0.35%. In addition, Cu, Ni, Cr, Mo, V, Nb and B must be reported.
What is the difference between A694 F52 and A105?
A105 flanges have 250 MPa (36 ksi) yield, whereas A694 F52 has 360 MPa (52 ksi). Therefore, F52 is used on high-strength X52 pipelines, while A105 is used for general plant piping.
Which pipe and fittings are used with F52 flanges?
A694 F52 flanges are used with API 5L X52 line pipe and MSS SP-75 / ASTM A860 WPHY 52 buttweld fittings.
Does A694 require impact testing?
No. A694 itself has no Charpy or hardness requirement. However, pipeline specifications usually add them, so state them on the order.
What is the difference between F52, F60 and F65?
They differ in yield strength: F52 has 360 MPa, F60 has 415 MPa and F65 has 450 MPa. As a result, each flange grade is matched to the X-grade of the pipe.
Global Supply
ASC LLP supplies ASTM A694 F52 flanges from Mumbai to customers in India, the Middle East, Europe, Africa, the Americas and South-East Asia. To get a prompt quotation, simply send your enquiry with flange type, size, class, facing, pipe OD and wall, and quantity.
Countries We Export To
UNITED STATES, EUROPE, UK, UAE, SAUDI ARABIA, OMAN, KUWAIT, JORDAN, QATAR, INDONESIA, MALAYSIA, BRAZIL, SPAIN, ITALY, FRANCE, GERMANY, BAHRAIN, SRI LANKA, AZERBAIJAN, AUSTRALIA, AUSTRIA, PHILIPPINES, TURKEY, RUSSIA, IRAN, IRAQ, CANADA, KOREA, JAPAN, YEMEN, FINLAND, ZIMBABWE, HUNGARY, PORTUGAL, VIETNAM, MOROCCO, THAILAND, SOUTH AFRICA, MEXICO, SINGAPORE, GREECE, KUWAIT, POLAND, NEW ZEALAND, SWEDEN, SWITZERLAND, BELGIUM, BHUTAN, BANGLADESH, TAIWAN, ROMANIA, CAMBODIA, KAZAKHSTAN, AFGHANISTAN.
