SM490YA Low-Alloy High-Strength Steel Plate

What is SM490YA Low-Alloy High-Strength Steel Plate?

 

SM490YA is a Japanese standard (JIS) low-alloy high-strength steel plate, manufactured in accordance with the JIS G3106 Special Technical Specification 3. This steel plate is renowned for its exceptional comprehensive properties, including high strength, superior toughness, impact resistance, wear resistance, and corrosion resistance, combined with excellent weldability and ease of processing.

 

Key Features:

High yield strength (≥ 325 MPa)

Excellent weldability

Good low-temperature toughness

Strong resistance to deformation

Suitable for heavy-duty structural applications

 

Standard and Delivery Condition

Item	Details
Executive Standard	JIS G 3106-2004
Delivery Condition	Hot Rolled, Normalized, Quenched + Tempered, or Tempered

 

It is extensively applied across various sectors of the machinery manufacturing industry, such as general mechanical equipment, heavy-duty machinery, vehicle components, cranes, mining machinery, and coal mining equipment. Furthermore, it is partially utilized in the fabrication of high-pressure vessels and high-pressure boiler equipment.

 

As a specialized steel for construction machinery, it is primarily used for the undercarriage components of crawler-type equipment (such as excavators). It is a key material for "undercarriage systems" (often referred to as the "four wheels and one belt" products), including components such as track links, track rollers, pin bushings, and track shoes. Additionally, it is widely used for boom pins, structural supports, and hydraulic components.

 

Product Overview and Grade Nomenclature

 

Standard Definition: Complies with the JIS G3106-2004 specification and meets the requirements of "Special Technical Specification 3".

 

Grade Analysis:

S (Steel): Represents steel materials.

M (Marine/Welding): Denotes suitability for welded structures.

490: Refers to the lower limit of tensile strength, which is 490 MPa.

YA / YB: Specific grade classifications. Grade A generally indicates that there is no requirement for impact energy (toughness testing); YB is similar to the Chinese national standard (GB) high weather-resistant structural steel Q345GNHL, while YA is similar to Q345GNH.

 

Dimensions and Processing Services

 

 

Thickness Specifications:

SM490YA/YB: Can be produced up to a maximum thickness of 150mm upon mutual agreement (standard thickness is≤100mm).

(Comparison: SM490A max thickness 300mm; SM490B/C max thickness 250mm).

 

SM490YA steel plates are available in a wide range of specifications to meet diverse industrial requirements:

 

Size Specifications:

10 – 50 mm (Thickness) * 2000 – 2400 mm (Width)

50 – 80 mm (Thickness) * 2000 – 2300 mm (Width)

80 – 120 mm (Thickness) * 2000 – 2400 mm (Width)

Other custom specifications are also available.

 

Available In-Stock Sizes (Examples):

10 * 2000 – 2500 * 9000 mm

15 * 2000 – 2500 * 9000 mm

(Various other stock dimensions ready for immediate shipping).

 

Value-Added Services:
We provide professional precision cutting based on technical drawings and deep processing services for all the above dimensions. Customizations can be discussed and finalized upon negotiation to ensure the product meets your specific engineering needs.

 

Read More: The Comprehensive Guide to Medium and Heavy Steel Plates

 

 

Chemical Composition - Heat Analysis Steel Grade Thickness C Si  Mn  P S SM490YA ≤100mm≤100mm ≤0.20≤0.20 ≤0.55≤0.55 ≤1.65≤1.65 ≤0.035≤0.035 ≤0.035≤0.035   Mechanical Properties   1. Yield Strength and Tensile Strength Steel Grade Thickness (mm) Yield Point or Yield Strength (N/mm2)  Tensile Strength (N/mm2) SM490YA ≤16≤16 ≥365≥365 490−610490−610   16 ≥355≥355 490−610490−610   40 ≥335≥335 490−610490−610   75 ≥325≥325 490−610490−610   100 - -   2. Elongation Steel Thickness (mm) Test Specimen No. Elongation (%) ≤5 No. 5 ≥19 5 No. 1A ≥15 5 No. 1A ≥19 >40 No. 4 ≥21

 

 

SM490YA high strength low alloy steel plate implementation standards: the implementation of the Japanese Industrial Standard JIS G3106

SM490YA high strength low alloy steel sheet size, shape, weight and permissible deviation:The size, shape, weight and permissible deviation of the steel plate shall conform to JIS G 3192, JIS G 3193, JIS G 3194. In this case, the permissible deviation of the width of the steel plate and the cut edge steel strip shall be in accordance with the deviation of class A of JIS G 3193, if no special provisions are made.

Delivery state of SM490YA low alloy structural steel plates: for thickness <80mm, the delivery state is hot rolled; for thickness ≥80mm, the delivery state is normalized . Delivery state can also be specified according to technical requirements.

SM490YA high strength steel plate thickness direction performance requirements: Z15, Z25, Z35.

SM490YA high tensile steel plate flaw detection requirements: one probe, two probe, three probe.

SM490YA high strength steel sheet is mainly used in buildings, bridges, ships, railroad cars, petroleum storage tanks, containers and other constructions which need high grade weldability.

 

Market Availability and Technical Highlights of SM490YA

I. Market Supply and Integrated Services

Currently, SM490YA steel plates are supplied by several leading enterprises, including Dongguan Zhaowang Metal Materials Co., Ltd. These suppliers provide one-stop integrated solutions, encompassing ordering, precision processing, warehousing, and logistics/transportation, ensuring a seamless supply chain for global clients.

 

II. Ready-to-Ship Stock Dimensions

We maintain an extensive inventory of SM490YA plates with the following standard specifications:

Thickness: 10 – 50 mm

Width: 2000 – 2500 mm

Length: 9000 mm

Custom Fabrication: Beyond stock sizes, we offer precision cutting according to technical drawings and deep processing services based on specific project negotiations.

III. Exceptional Performance: The "All-Rounder" in Industry

 

As a high-strength low-alloy (HSLA) steel, SM490YA is a versatile choice for construction, bridge engineering, and machinery manufacturing.

 

Mechanical Strength: With a yield strength of ≥ 490 MPa and tensile strength of 590 – 750 MPa, its performance is highly competitive within its class.

 

Workability: Outstanding weldability and cold-bending properties significantly simplify on-site construction and enhance overall engineering efficiency.

 

IV. Versatile Structural Profiles (Section Steel)

JIS SM490YA is available in various profiles, including H-beams, Angle steel, and Channel steel, catering to different structural needs:

 

H-Beams: Widely utilized in bridge construction and high-rise structural frames due to their economically efficient cross-section, superior mechanical properties, and exceptional load-bearing capacity.

 

Case Study: In a recent large-scale bridge project, SM490YA H-beams were used as the primary load-bearing structure, resulting in significant material savings while enhancing the bridge's safety and long-term durability.

 

V. Advanced Surface Treatment and Durability

To ensure a long service life in outdoor environments, SM490YA profiles typically undergo advanced surface treatments such as galvanizing or industrial painting. These coatings effectively prevent corrosion, reducing maintenance frequency and costs-a critical factor for infrastructure longevity.

 

VI. Market Growth and Global Export

Between 2021 and 2025, total shipments reached 10,000 tons, with an average annual order growth rate of 3%. Due to its premium multi-performance characteristics, this grade has earned widespread recognition and high praise across the manufacturing sector. It has steadily become one of the top export grades for GNEE, reflecting its growing dominance in the international steel market.

 

What is SM490A steel equivalent to?

SM490A steel is roughly equivalent to ASTM A572 Grade 50 in terms of its properties and applications.

 

what's the difference between SM490YA and SM490A?

 

SM490YA is a specialized high-yield version of the standard SM490A structural steel under the JIS G3106 series, specifically optimized for the demanding load-bearing requirements of heavy machinery and undercarriage components.

 

1.The letter "Y" in SM490YA stands for higher Yield Strength.

SM490A: A standard grade for general welded structures. It has a lower yield point compared to the YA grade.

SM490YA: Specifically designed to provide a higher yield-to-tensile ratio. It can withstand higher stress before deforming permanently.

 

Mechanical Property Comparison (for thickness≤16mm)

Property	SM490A	SM490YA	Difference
Yield Strength (ReL)	≥325MPa	≥365MPa	YA is ~12% stronger
Tensile Strength (Rm)	490−610MPa	490−610MPa	Same
Impact Testing	Not required	Not required	Both are "A" level

 

Maximum Thickness Capability

According to the technical data provided:

SM490A: Can be produced up to a thickness of 300mm. It is more suitable for extra-thick structural components.

SM490YA: Generally limited to a maximum thickness of 150mm (under agreement). It is optimized for high-performance parts rather than extreme thickness.

 

Application Differences

SM490A is used for general structural purposes where standard 490MPa tensile strength is sufficient, such as buildings, bridges, and general steel frames.

 

SM490YA is used for high-load mechanical components, especially in the construction machinery industry. It is the preferred material for undercarriage parts (the "four wheels and one belt" system) like track links and rollers, which require high load-bearing capacity and wear resistance.

 

Summary

Choose SM490A if you need a cost-effective, standard structural steel or if the plate needs to be extremely thick (>150mm).

Choose SM490YA if your design requires a higher safety margin for yield strength or if you are manufacturing heavy machinery parts that face intense mechanical stress.

 

 

SM490YA has several equivalent grades in international standards:

Standard	Grade
ASTM	A572 Grade 50
EN	S355JR / S355J0
GB	Q345B

This makes it easier for global buyers to find compatible materials for their projects.

 

 

SM490YA steel plate is widely used in various industries:

• Building structures and steel frames
• Bridges and infrastructure projects
• Construction machinery
• Shipbuilding and offshore platforms
• Pressure-resistant structural components

Its high strength-to-weight ratio makes it ideal for reducing material usage while maintaining structural integrity.

 

 

Choosing GNEE Steel means choosing reliability and performance:

 

1. Strict Quality Control

All plates are produced under international standards with full inspection and traceability.

 

2. Flexible Customization

Thickness: 6mm – 300mm

Width: up to 3500mm

Length: up to 18000mm

Cutting, drilling, and surface treatment available

 

3. Complete Certification

Mill Test Certificate (MTC)

Third-party inspection (SGS, BV, TUV)

 

4. Global Export Experience

GNEE has supplied SM490YA plates to Southeast Asia, the Middle East, Europe, and South America.

 

 

When selecting structural steel, understanding the differences between SM490YA and other common grades is essential for optimal project performance.

 

Property / Grade	SM490YA	SS400	ASTM A36	S355JR
Standard	JIS G3106	JIS G3101	ASTM	EN 10025
Yield Strength	≥ 325 MPa	≥ 245 MPa	≥ 250 MPa	≥ 355 MPa
Tensile Strength	490–610 MPa	400–510 MPa	400–550 MPa	470–630 MPa
Weldability	Excellent	Good	Good	Excellent
Strength Level	High Strength	Mild Steel	Mild Steel	High Strength
Typical Use	Bridges, heavy structures	General structures	General fabrication	Structural engineering

 

Key Differences:

Higher Strength than SS400 & A36
SM490YA provides significantly better load-bearing capacity, making it suitable for heavy-duty applications.

Comparable to S355JR
While S355JR has slightly higher yield strength, SM490YA offers better compatibility with JIS-standard projects.

Better Cost-to-Performance Ratio
SM490YA is an ideal balance between performance and cost for Asian and international markets.

 

 

SM490YA offers a balanced combination of strength, weldability, and cost-efficiency. Compared to ordinary carbon steel, it significantly improves structural performance and reduces long-term maintenance costs.

Whether you are building bridges, factories, or heavy machinery, SM490YA is a reliable and economical choice.

 

 

What is SM490YA steel plate used for?

SM490YA is mainly used in bridges, buildings, construction machinery, and heavy structural components due to its high strength and excellent weldability.

 

What is the difference between SM490YA and SM490YB?

SM490YA: Standard strength with basic impact requirements

SM490YB: Improved impact toughness, especially suitable for low-temperature environments

 

Is SM490YA equivalent to S355JR?

Yes, SM490YA is often considered equivalent to S355JR in terms of application, but they follow different standards (JIS vs EN), and slight differences exist in chemical composition and mechanical properties.

 

Can SM490YA be welded easily?

Yes, SM490YA has excellent weldability due to its controlled carbon content and alloy composition. It is suitable for various welding processes such as MIG, TIG, and arc welding.

 

What thickness range can GNEE supply for SM490YA?

GNEE can supply:

Thickness: 6mm – 300mm

Width: up to 3500mm

Length: up to 18000mm
Custom sizes and cutting services are also available.

 

Does SM490YA require heat treatment?

Generally, SM490YA is supplied in hot-rolled condition. Heat treatment is not mandatory but can be applied depending on specific engineering requirements.

 

What certifications are available for SM490YA plates?

GNEE provides:

Mill Test Certificate (MTC)

Third-party inspection (SGS, BV, TUV)

EN 10204 3.1 / 3.2 certification

 

Is SM490YA suitable for offshore projects?

Yes, SM490YA can be used in offshore and marine structures, especially when combined with additional requirements like impact testing and corrosion protection.

 

How does SM490YA compare in price?

SM490YA is more expensive than SS400/A36, but more cost-effective than higher-grade alloy steels, offering an excellent balance between performance and price.

 

 

Get A Quote For SM490YA Steel Plate

 

Looking for a dependable supplier of SM490YA Low-Alloy High-Strength Steel Plate?

 

GNEE Steel is ready to provide:

• Competitive prices
• Fast delivery
• Professional technical support

Contact us today to get a customized quote and technical consultation.

 

 

 

 

 

 

 

 

Our products have undergone strict quality testing and come with professional certificates. If you have any questions about SM490YA High Strength Steel Plate, please feel free to inspect.

 

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