ASTM A709 Steel Plate for Bridges: High-Strength, Low-Alloy Structural Steel

ASTM A709 Overview

ASTM A709 steel plate is a high-strength, low-alloy structural steel specifically developed for bridge construction and other load-bearing structures. It offers excellent toughness, weldability, and durability in demanding environments.
The ASTM A709 range includes multiple grades, such as Grade 50, Grade 50W weathering steel, and Grade HPS 70W, each designed for specific engineering requirements.

CJM supplies a full range of ASTM A709 grades, available in various thicknesses and dimensions to meet international bridge engineering requirements. These plates are hot-rolled and available in roll, normalized or thermomechanical (TMCP) conditions for superior performance.

Available Grades

• ASTM A709 Grade 36
• ASTM A709 Grade 50
• ASTM A709 Grade 50W
• ASTM A709 Grade HPS 50W
• ASTM A709 Grade HPS 70W

ASTM A709 Grade HPS 70W is ideal for applications requiring both high strength and fracture resistance, while A709-50 plate offers a balance of strength and weldability for general use. Grade 50W Corten-type weathering steel forms a protective oxide layer, minimizing the need for painting in exposed bridge structures.

We supply both standard and astm 709 heavy steel plate in thicknesses up to 200mm, meeting the needs of large-span bridges and heavy-load structures.

Thickness and Heavy Plate Supply

Specification	Range
Thickness	6 mm – 200 mm
Width	1500 mm – 3200 mm
Length	6000 mm – 18000 mm
Delivery Condition	Hot Rolled, Normalized, TMCP
Standard	ASTM A709 / ASME SA709

Our A709 heavy steel plate is suitable for critical structural components such as bridge girders, gusset plates, and tower segments.

Mechanical Properties

Grade	Yield Strength (MPa)	Tensile Strength (MPa)	Elongation (%)	Charpy Impact
A709 Gr. 36	≥ 250	400–550	≥ 20	Optional
A709 Gr. 50	≥ 345	485–620	≥ 21	Optional
A709 Gr. 50W	≥ 345	485–620	≥ 21	Improved CVN
HPS 50W	≥ 345	485–620	≥ 21	-23°C
HPS 70W	≥ 485	585–760	≥ 18	-23°C

Chemical Composition (% by weight)

Grade	C	Mn	Si	P (max)	S (max)	Cu	Cr	Ni
A709 Gr. 50	≤0.23	0.85–1.35	≤0.40	0.035	0.045	—	—	—
A709 Gr. 50W	≤0.19	0.85–1.35	0.15–0.50	0.035	0.045	0.25–0.40	0.40–0.65	≤0.40
HPS 50W	≤0.11	1.20–1.60	0.15–0.50	0.020	0.010	0.25–0.40	0.40–0.70	0.40–0.75
HPS 70W	≤0.14	1.35–1.65	0.15–0.50	0.020	0.010	0.25–0.40	0.40–0.70	0.40–0.75

ASTM A709 Typical Applications

• Highway and railway bridges
• Pedestrian overpasses
• Heavy-load structural supports
• Marine and coastal structures using Grade 50W weathering steel

Explore our full range of bridge steel plates for different load conditions and corrosion environments.

Technical Specification

• Standard: ASTM A709 / A709M
• Delivery Condition: As rolled, Normalized, TMCP, or Quenched & Tempered
• Heat Treatment: HPS grades are usually delivered in Q+T or TMCP condition
• Weathering resistance: HPS 50W/70W meet atmospheric corrosion requirements equivalent to ASTM A588

Processing and Supply Capabilities

We offer processing services for A709 steel plate, including cutting, beveling, drilling, and surface preparation.
For buyers looking for a reliable A709 rolled plate supplier, we provide:

• Mill certificates and full traceability
• Third-party inspection
• Fast delivery from stock or mill production
• Global shipping support

Delivery Conditions

ASTM A709 plates can be supplied in:

• As-rolled ASTM A709 – Cost-effective option for projects that do not require additional heat treatment.
• Normalized – For improved toughness and dimensional stability.
• TMCP (Thermo-Mechanically Controlled Processed) – For superior strength and weldability.

You may also be interested in our weathering steel plate category for broader corrosion-resistant applications.

Frequently Asked Questions

• Q1: What’s the difference between A709 Gr.50 and HPS 50W?
  A709 Gr.50 is a standard carbon steel bridge plate, while HPS 50W adds weathering resistance and is optimized for long-term performance with fewer maintenance cycles.
• Q2: Can A709 steel plates be used in marine environments?
  Yes—especially HPS 50W and HPS 70W grades, which provide strong corrosion resistance in coastal or high-humidity areas.
• Q3: What is the meaning of “HPS” in A709 steel?
  HPS stands for High-Performance Steel—a class of steels that meet stringent requirements for weldability, toughness, and weathering properties.
• Q4: Is ASTM A709 the same as corten steel?
  Not exactly—only A709 Grade 50W and HPS 70W exhibit similar weathering behavior to corten steel.
• Q5: Can A709 be used for marine bridges?
  Yes, especially HPS grades with enhanced corrosion resistance.
• Q6: Is A709 heat-treated?
  Some grades like HPS 70W are delivered in TMCP or quenched and tempered conditions for improved toughness.

Why Choose Our Bridge Steel Plate & Coil?

CJM is a trusted bridge steel plate supplier in China, offering:

• Full grade coverage from Grade 36 to HPS 70W
• Fast delivery from over 1 million tons in stock
• Customized cutting and logistics solutions
• Extensive export experience to Europe, Southeast Asia, Africa, and the Americas
• Technical support for project-specific requirements

Packaging & Shipping for Bridge Steel Plate & Coil

We ensure safe, damage-free delivery of your Bridge Steel Plates and Coils using durable, industry-standard packaging.

• Plates: Wrapped with protective materials to prevent handling damage.
• Coils: Strapped and wrapped in heavy-duty plastic or corrosion-resistant material for weather protection.

Features: Waterproof wrapping, reinforced pallets for stability, and custom packaging for special requirements.

CJM offers fast and efficient shipping to major international markets, and work with trusted logistics partners to guarantee timely delivery and minimize any risk of delay. Our dedicated support team is available to answer any shipping-related inquiries.

Shipping time and cost depend on your location and the order volume. Please contact us for detailed quotes and estimated delivery times for your specific project.

Looking for reliable A709 Gr.50 / HPS 50W / HPS 70W steel plates?

Contact us today for more information on our Bridge Steel Plate and Bridge Steel Coil solutions. We offer competitive pricing and tailored support to meet your project’s specific requirements.

WhatsApp: +86 18191906640
Email: info@cjmstainlesssteel.com

Q: What is your company’s main products/services?

A: We are a professional manufacturer for Carbon Steel, Alloy Steel and Profile products. We have the experience of steel business for more than 10 years and our products are exported to Mid East,South America,Southeast Asia,Africa,South and East Asia etc.

Q: Can I go to your factory for a visit?

A: Of course, we welcome customers from all over the world to visit our factory.

Q: What are your terms of payment?

A: 30% T/T deposite and 70% balance before shipment.

Q: What is your delivery time?

A: For stocks,we could transport the goods to loading port within 7 days after we received the deposit; For production,it usually takes about 15-30 days after receiving the deposit.

Q: Do you provide samples? Are they free or paid?

A: Samples are available for free,but the courier freight will be covered by customer account.

Q: Do you accept the third party inspection?

A:Yes, we fully accept ‌third-party inspections.

Q: Why should I buy from you not from other suppliers?

A: Integrating the superior resources of China’s steel industry, we provide customers with high-quality steel products at preferential prices, and can ensure that the goods are delivered to customers in a timely manner.

Q:How can you guarantee quality?

A: Always a pre-production sample before mass production;Always 100% inspected before shipment