ASTM A514 Grade B High Strength Steel: Properties, Applications, and Advantages
ASTM A514 Grade B is a high-strength, quenched and tempered alloy steel plate, primarily used in structural applications that demand both exceptional strength and good weldability. Developed to handle extreme loads and stress, A514 Grade B is commonly seen in construction equipment, heavy cranes, bridges, and military armor applications.
This blog explores the key characteristics, mechanical properties, and use cases of ASTM A514 Grade B, making it easier for engineers, fabricators, and project managers to decide if it’s the right fit for their next project.
What is ASTM A514 Grade B?
ASTM A514 is a specification from the American Society for Testing and Materials (ASTM) that covers high-yield-strength, quenched and tempered alloy steel plates. Grade B is one of the most common grades in the A514 family.
Key Features
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High yield strength: 100 ksi (690 MPa) minimum
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Quenched and tempered for toughness
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Good formability and weldability
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Thickness range: Usually supplied between 3/16″ to 6″ (5mm–150mm)
Mechanical Properties of ASTM A514 Grade B
| Property | Value |
|---|---|
| Yield Strength | ≥ 100 ksi (690 MPa) |
| Tensile Strength | 110–130 ksi (760–895 MPa) |
| Elongation (in 2″) | ~18% |
| Brinell Hardness | 235–293 HB |
| Charpy Impact Toughness | Required at −20°F (−29°C) |
These mechanical properties make A514 Grade B an ideal material for heavy-load structures and impact-resistant applications.
Chemical Composition (Typical % by Weight)
| Element | Composition |
|---|---|
| Carbon (C) | 0.12 – 0.21% |
| Manganese (Mn) | 0.90 – 1.50% |
| Phosphorus (P) | ≤ 0.025% |
| Sulfur (S) | ≤ 0.025% |
| Chromium (Cr) | 0.40 – 0.65% |
| Molybdenum (Mo) | 0.15 – 0.25% |
| Vanadium (V) | 0.03 – 0.10% |
| Nickel (Ni) | 0.40 – 0.90% |
The combination of chromium, molybdenum, vanadium, and nickel enhances hardenability, strength, and toughness in A514 steel.
Applications of A514 Grade B Steel
ASTM A514 Grade B is specifically engineered for applications where strength-to-weight ratio, impact resistance, and formability are critical.
1. Construction Equipment
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Boom sections for cranes
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Bulldozer blades
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Heavy machinery frames
2. Bridge Construction
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Load-bearing members
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Structural supports in trusses and box girders
3. Military and Defense
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Armor plating for military vehicles
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Blast protection structures
4. Offshore and Marine
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Oil platform structures
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Decks and subsea modules
Advantages of ASTM A514 Grade B
High Strength with Reduced Weight
With a minimum yield strength of 100 ksi, A514 enables designers to reduce the material’s thickness, resulting in lighter structures without compromising load capacity.
Excellent Toughness
Quenching and tempering enhance impact resistance, making A514 suitable for low-temperature applications and dynamic loading.
Weldability
Despite its high strength, A514 Grade B maintains good weldability when proper preheat and post-weld procedures are followed. It meets AWS D1.1 weld code requirements.
Cost-Efficiency in Large Projects
Although the cost per pound is higher than mild steel, less material is required due to its superior strength, often resulting in total cost savings.
Welding and Fabrication Considerations
A514 Grade B can be welded successfully with proper procedures, but certain precautions must be taken due to its high strength.
Preheat Recommendations
| Plate Thickness | Preheat Temp |
|---|---|
| Up to 1.5″ (38 mm) | 50–125°F (10–50°C) |
| 1.5″–2.5″ (38–63 mm) | 125–175°F (50–80°C) |
| Over 2.5″ (63 mm) | 175–225°F (80–110°C) |
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Avoid hydrogen-induced cracking by using low-hydrogen electrodes (e.g., E11018-M).
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Avoid excessive heat input that could affect toughness.
A514 vs Other High-Strength Steels
| Steel Grade | Yield Strength | Weldability | Typical Use Case |
|---|---|---|---|
| A36 | 36 ksi | Excellent | General structural use |
| A572 Grade 50 | 50 ksi | Very Good | Bridges, buildings |
| A514 Grade B | 100 ksi | Good (with care) | Cranes, heavy machinery |
Compared to other grades, A514 offers the best combination of strength and weight reduction, although it requires more attention during fabrication.
Common Plate Sizes and Availability
Steel suppliers like Midwest Steel, Leeco Steel, and others typically stock A514 Grade B in:
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Widths: 48″–120″ (1219–3048 mm)
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Lengths: 96″–480″ (2438–12192 mm)
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Thickness: 3/16″ to 6″ (5 mm to 150 mm)
Always check for mill certification and heat treatment records, especially if using A514 in safety-critical applications.
Is A514 Grade B Right for Your Project?
You should consider ASTM A514 Grade B if:
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You require high load-bearing capacity with reduced weight
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Your structure will face harsh or dynamic conditions
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Welding can be done under controlled procedures
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You want a durable and long-lasting steel solution
Final Thoughts
ASTM A514 Grade B steel is a premium material for high-performance structural applications. Its strength, toughness, and reliability make it the material of choice for engineers who can’t afford failure under extreme stress.
However, its proper use requires careful handling, welding procedures, and quality control—making supplier expertise critical. When working with A514 Grade B, partnering with experienced steel providers like Midwest Steel ensures you’re getting certified material with expert support for processing and fabrication.
