ASTM A694/A694M is the standard specification by ASTM International covering carbon and alloy steel forgings used for pipe flanges, fittings, valves, and parts intended for high-pressure liquid and gas transmission service. Grades are designated by their minimum yield strength (F42 through F70). The companion specification ASME SA-694 adopts identical requirements for ASME Boiler and Pressure Vessel Code compliance. 

Zhengzhou Huitong (HT Pipe) supplies ASTM A694 / SA-694 compliant forged flanges and fittings across all standard grades with full Mill Test Certificates (MTC) per EN 10204 3.1 and full traceability per ASTM A961.

1. Standard Scope & Designation

ASTM A694/A694M covers carbon and alloy steel forgings for high-pressure transmission pipeline components. These forgings are designed for use with high-strength transmission-service pipe per ASTM A53, A106, A381, API 5L, and MSS SP-75. Products must be suitable for welding to the associated pipe and fitting materials.

2. Grades Covered by ASTM A694

ASTM A694 covers nine grades (F42 through F70), designated by their minimum yield strength in ksi. Grades F42 through F56 are typically carbon steel or HSLA steel; F60 through F70 are high-strength low-alloy (HSLA) or alloy steel for maximum pressure ratings.

2.1 SI/Metric Grade Equivalents (A694M)

3. Chemical Composition — Heat Analysis (ASTM A694 Table 2)

Values are maximum unless shown as a range. Residual elements (Cu, Ni, Cr, Mo, V, Cb) must be reported per heat but have no specified limits. Product analysis tolerances per ASTM A961 apply. Alloy steel grades must conform to Grade L5 of A707/A707M.

Note: Heat analysis must be performed per ASTM A961. Product analysis tolerances per ASTM A961 Table apply. Residual elements must be reported — their absence or presence at any level is not cause for rejection unless product analysis deviates beyond stated tolerances.

4. Mechanical Property Requirements (ASTM A694 Table 1)

All values are minimum requirements after required heat treatment. Per ASTM A694/A694M-16. Testing per ASTM A370.

Note: F70 has 18% minimum elongation vs. 20% for all other grades. Reduction of area (RA) requirements are not specified in A694 Table 1 but may be specified in the purchase order. Hardness requirements per A961.

5. Heat Treatment Requirements

All ASTM A694 forgings must be heat treated after forging and prior to final delivery. The choice of heat treatment depends on the steel type and grade. Permitted heat treatment methods are listed below.

6. Testing & Inspection Requirements

7. Manufacturing & Melting Requirements

8. Flange Types & Compatible Grades

ASTM A694 forgings are manufactured to dimensional standards ASME B16.5 (NPS ½–24) and ASME B16.47 (NPS 26–60). Common flange types and their typical A694 grade availability:

Flange Face Types: Raised Face (RF), Flat Face (FF), Ring Joint (RTJ), Tongue & Groove (T&G), Male & Female (M&F). Dimensional requirements per ASME B16.5 (NPS ½–24) and ASME B16.47 Series A & B (NPS 26–60). Large diameter pipeline flanges per MSS SP-44.

9. Related Standards & Companion Specifications

10. A694 vs A182 vs A105 — Flange Material Specifications Compared

11. How to Order — Required Information

12. Frequently Asked Questions

Q: What is ASTM A694 stainless steel flanges?

ASTM A694 covers carbon and alloy steel forgings — NOT stainless steel. The specification is specifically for high-pressure transmission pipeline flanges, fittings, valves, and parts. Stainless steel flanges are covered by ASTM A182 (forged alloy/stainless) or ASTM A240 (plate). A694 grades F42 through F70 are carbon or HSLA steel with yield strengths from 42 to 70 ksi.

Q: What are the mechanical properties of ASTM A694 F60?

ASTM A694 F60 (UNS K02602): minimum yield strength 60 ksi (415 MPa), minimum tensile strength 75 ksi (515 MPa), minimum elongation 20% in 2 inches (per ASTM A370). F60 is a high-strength low-alloy or alloy steel grade, typically requiring Quenched + Tempered heat treatment and conforming to ASTM A707 Grade L5 chemistry.

Q: What is the difference between ASTM A694 F52 and F65?

F52 has a minimum yield of 52 ksi (360 MPa) and tensile of 66 ksi (455 MPa), typically used for standard high-pressure transmission pipeline flanges. F65 has a minimum yield of 65 ksi (450 MPa) and tensile of 77 ksi (530 MPa), designed for extreme high-pressure and deepwater subsea pipeline applications. F65 also requires stricter alloy chemistry per A707 Grade L5 and typically requires Q+T heat treatment.

Q: What heat treatment is required for A694 F70 forgings?

F70 (alloy steel, 70 ksi min yield) must be heat treated by Quenching + Precipitation Aging Treatment at 1000–1225°F (540–665°C). The minimum tempering temperature of 1000°F (540°C) applies. All weld repairs must be completed before this heat treatment cycle to ensure the weld zone achieves the required mechanical properties.

Q: Can ASTM A694 flanges be used with API 5L pipe?

Yes. ASTM A694 forgings are specifically designed for use with high-strength transmission-service pipe conforming to ASTM A53, A106, A381, API 5L, and MSS SP-75. The flange bore, wall thickness compatibility, and weld end preparation (BW or SW) should be coordinated with the applicable ASME B16.5 or B16.47 dimensional standard and the associated pipe specification.

Q: What is ASTM A961 and why is it important for A694?

ASTM A961/A961M is the "Common Requirements Specification for Steel Flanges, Forged Fittings, Valves, and Parts" that supplements ASTM A694. It provides the manufacturing, testing, certification, marking, and quality requirements that are common across multiple flange and forging specifications. Per A694, in case of conflict between A694 and A961, A694 takes precedence. Non-compliance with A961 is treated as non-compliance with A694.

Request a Quote — ASTM A694 Carbon & Alloy Steel Flanges & Forgings

Zhengzhou Huitong (HT Pipe) supplies ASTM A694 / SA-694 compliant forged flanges and fittings in grades F42, F52, F56, F60, F65, and F70. Full EN 10204 3.1 CMTRs, PMI certification, and competitive lead times from our manufacturing facility in China.