ASTM A514 Grade F is a high-yield, quenched and tempered alloy steel plate primarily used for structural applications where weight savings and high strength are critical. It is part of a family of steels often referred to by the trade name T-1 steel.
Key Specifications
Yield Strength: Minimum 100 ksi (approx. 690 MPa) for thicknesses up to 2.5 inches.
Tensile Strength: Typically 110–130 ksi.
Condition: Delivered in a quenched and tempered state to achieve its high-strength and tough mechanical properties.
Thickness Range: Standard availability for Grade F is typically up to 2.5 inches (63.5 mm).
The closest and most widely accepted European equivalent to ASTM A514 Grade F is EN 10025-6:2019 grade S690QL1 (or S690Q/QL/QL1).
Here is a detailed breakdown of the equivalency and critical distinctions:
Direct Technical Comparison
| Property | A514 Grade F (ASTM A514) | European Equivalent: S690QL1 (EN 10025-6) |
|---|---|---|
| Minimum Yield Strength (ReH) | 690 MPa (up to 31.75 mm) | 690 MPa (up to 30 mm) |
| Tensile Strength (Rm) | 760 - 895 MPa | 770 - 940 MPa |
| Delivery Condition | Quenched & Tempered | Quenched & Tempered (as per "Q") |
| Impact Toughness | Charpy V-notch, min. value @ -46°C (-50°F) | Charpy V-notch, min. value @ -60°C (for QL1) |
| Key Purpose | High strength with improved weldability (lower CE) | High-strength weldable structural steel |
Why S690QL1 is the Best Match:
Strength: The "690" denotes a 690 MPa minimum yield strength, which is a direct match for Grade F.
Process: The "Q" confirms it is quenched and tempered.
Toughness: The "L1" sub-grade ensures impact testing at -60°C, which closely aligns with Grade F's stringent -50°F (-46°C) requirement. Standard S690QL (tested at -40°C) may not meet the toughness specification.
Important Considerations & Caveats
Not a "Drop-in" Substitute: While mechanically similar, they are governed by different standards systems (ASTM vs. EN). Substitution requires formal approval under the applicable design code (e.g., Eurocode 3 vs. AISC).
Chemical Composition: The alloy systems differ. A514 Grade F uses a specific Cr-Mo balance (without boron), while S690QL1 typically uses a Mn-Ni-Mo-B system. This leads to different Carbon Equivalent (CEV/Pcm) values, affecting welding procedures.
Pressure Vessel Use: If the A514 Grade F is for a pressure vessel application, a closer functional equivalent in Europe might be P690QH according to EN 10028-6 (pressure vessel steel plate).
Certification: When procuring S690QL1 as an equivalent, you must explicitly specify the required toughness sub-grade (L1) and thickness range to ensure compliance.
Practical Recommendation
For a structural design switch from A514 Grade F to a European steel:
Specify S690QL1 to match both strength and low-temperature toughness.
Re-qualify all welding procedures using appropriate EN-compliant consumables (e.g., EN ISO 16834-A).
Have the substitution reviewed and approved by the responsible design engineer, noting the change in standard and material designation.
In summary, the primary European equivalent is S690QL1, but successful substitution requires careful attention to toughness grades, welding procedures, and governing design codes.
1. What is A514 Grade F steel used for?
A514 Grade F is primarily used in high-strength structural applications like heavy construction equipment, crane booms, mining machinery, and bridges where a superior strength-to-weight ratio is required.
2. What is the yield strength of A514 Grade F?
For plates up to 1.25 inches (31.75 mm) thick, the minimum yield strength is 100 ksi (690 MPa). For thicker plates, the yield strength decreases, typically to 90 ksi (620 MPa) up to 2.5 inches.
3. Can A514 Grade F be welded?
Yes, it can be welded, but it requires strict procedures including preheating, the use of low-hydrogen electrodes, and often post-weld heat treatment to prevent cracking due to its high hardenability.
4. How does A514 Grade F differ from Grade E?
The main difference is in chemistry: Grade F has lower carbon and alloy content (and no boron), resulting in better weldability and a lower carbon equivalent, while both grades offer the same minimum yield strength.
5. What is the hardness of A514 Grade F?
The typical hardness range for A514 Grade F is approximately HBW 280-340 (Brinell) or HRC 29-36, but hardness is not a specified property in the ASTM standard.
6. Is A514 Grade F the same as T1 steel?
Yes, A514 Grade F is often commercially referred to as "T1 Type F" or "modified T1." The "T1" name originally came from a trademark, but it's commonly used for this family of high-strength, quenched and tempered steels.
7. What is the European equivalent of A514 Grade F?
The closest European equivalent is S690QL or S690Q/QL1 according to EN 10025-6, which has a similar 690 MPa yield strength and quenched & tempered condition.
8. Can you flame cut A514 Grade F?
Yes, but it requires preheating (typically 300-500°F) and controlled cooling to prevent hardening and cracking along the cut edge. Plasma or waterjet cutting are often preferred alternatives.
9. What is the chemical composition of A514 Grade F?
It has a lower carbon content (max 0.20%) compared to Grade E, along with reduced levels of chromium, molybdenum, and no boron, resulting in a lower carbon equivalent for improved weldability.
10. Why choose A514 Grade F over Grade E?
Choose Grade F when weldability and fabrication ease are top priorities for complex structures, as its leaner chemistry reduces the risk of welding-related cracking compared to the higher-alloy Grade E.
Full specification and details are available on request. The above information is provided for guidance purposes only. For specific design requirements please contact our technical sales staff.
