ASTM A694 F70 Carbon Steel Flanges – A694 Gr F70 High-Yield Pipeline Flanges
ASC LLP, Mumbai, supplies ASTM A694 F70 flanges: high-yield forged carbon steel weld neck, blind and special flanges for API 5L X70 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 F70 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 F70 means a 70 ksi (485 MPa) minimum yield. As a result, an F70 flange matches the strength of API 5L X70 line pipe, and it can be welded to X70 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 F70 – Quick Facts
- Specification: ASTM A694, Grade F70, so the chemical composition is the A694 one
- Strength: 485 MPa (70 ksi) yield / 565 MPa (82 ksi) tensile min
- F70 material: forged carbon (or low-alloy) steel, then heat treated
- Matching pipe: API 5L X70 (L485)
- Matching fittings: MSS SP-75 / ASTM A860 WPHY 70
- Standards: MSS SP-44, ASME B16.5, B16.47
A694 F70 Material – 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 | No limit; however, they must 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 F70 Mechanical Properties
| Property | A694 Grade F70 |
| Yield strength, min (0.2% offset) | 485 MPa (70 ksi) |
| Tensile strength, min | 565 MPa (82 ksi) |
| Elongation in 50 mm, min | 18% (F70 is the only A694 grade below 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, F70 goes with X70 and F60 with X60. In addition, elongation is 20% for every grade except F70, which needs 18%.
A694 F70 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 F70 Flanges Specifications
| Item | Details |
| Specification | ASTM A694, Grade F70 |
| Flange types | Weld neck and blind, as well as long weld neck, anchor and swivel flanges |
| Dimensions | MSS SP-44, ASME B16.5, ASME B16.47 Series A / B |
| Size | NPS ½ to 60, while larger sizes follow MSS SP-44 |
| Pressure class | 150, 300, 600, 900, 1500, 2500 |
| Facing | RF or FF; also RTJ for high classes |
| Bore | Matched to the pipe wall thickness, for example X70 SCH 40 / STD / XS |
| Heat treatment | Normalised, or alternatively 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; in addition, 3.2 on request |
A694 F70 Flanges – Matching Pipe, Fittings & Bolting
| Component | Matching grade |
| Line pipe | API 5L X70, either PSL1 or PSL2 |
| Buttweld fittings | MSS SP-75 / ASTM A860 WPHY 70, so the fittings match the yield too |
| Stud bolts / nuts | A193 B7 studs together with A194 2H nuts |
| Other grades | A694 F60 with WPHY 60; also F65 with WPHY 65 |
Because pipeline systems are designed on yield strength, every part should match the X70 pipe. By contrast, for plant piping at low temperature, A350 LF2 flanges are used instead, while A216 WCB covers cast valve flanges.
A694 F70 Flange Heat Treatment & Welding
- Heat treatment: A694 flanges are normalised, normalised and tempered, or quenched and tempered, so they reach the F70 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 F70 Flanges
| Application | Typical A694 F70 flange use |
| Oil & gas transmission | Flanged joints on X70 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 F70 Flanges Supplier – ASC LLP, Mumbai
ASC LLP supplies ASTM A694 F70 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 F52 and F60 flanges for other pipe grades.
Why Buy A694 F70 Flanges from ASC LLP?
- Traceable material: EN 10204 3.1 certificates, so each flange shows its chemistry, heat treatment and tensile results.
- Pipeline testing: in addition, Charpy, hardness and CE limits can be added to suit your pipeline specification.
- Matched bores: weld neck bores are machined to the X70 pipe wall, so the weld joint lines up.
- Complete packages: flanges together with WPHY 70 fittings and stud bolts, as well as F52 and F60 flanges.
Choosing F70 Flanges
F70 is the highest-strength grade in A694, so it is used only where the pipeline is designed on X70 pipe. However, higher strength also makes welding more demanding; therefore, specify a carbon-equivalent limit and a qualified welding procedure, and add Charpy and hardness tests where the line runs cold or sour.
Frequently Asked Questions – ASTM A694 F70 Flanges
What is the chemical composition of A694 F70?
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 ASTM A694 F70 material?
ASTM A694 F70 is a high-yield forged carbon steel for pipeline flanges and fittings, with 485 MPa (70 ksi) minimum yield and 565 MPa (82 ksi) minimum tensile strength.
What does F70 mean in A694?
The number gives the minimum yield strength in ksi. In other words, F70 has 70 ksi (485 MPa) minimum yield, so it matches API 5L X70 pipe.
What is the difference between A694 F70 and A105?
A105 flanges have 250 MPa (36 ksi) yield, whereas A694 F70 has 485 MPa (70 ksi). Therefore, F70 is used on high-strength X70 pipelines, while A105 is used for general plant piping.
Which pipe and fittings are used with F70 flanges?
A694 F70 flanges are used with API 5L X70 line pipe and MSS SP-75 / ASTM A860 WPHY 70 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 F60, F65 and F70?
They differ in strength: F60 has 415 MPa yield, F65 has 450 MPa and F70 has 485 MPa. In addition, F70 needs only 18% elongation, while the other grades need 20%.
Global Supply
ASC LLP supplies ASTM A694 F70 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.
