ASTM A588 Gr A Plate Supplier

ASTM A588 / ASME SA588 Grade A Corten B Weathering Steel Plates

Dinesh Tube India supplies ASTM A588 Grade A plates from Mumbai to bridge and structural fabricators, tower and chimney makers, rail-car builders and architectural steel contractors. ASTM A588 is the main US high-strength low-alloy weathering steel for structures, the standard grade behind Corten B. We supply Grade A, with Grades B and C on request, in full plates or cut sizes with EN 10204 3.1 mill test certificates.

A588 has low phosphorus, with vanadium, so it welds well in thick sections and is made in plates up to 200 mm. For thin cladding sheet, ASTM A242 (Corten A) is often used instead. For all Corten grades, see our Corten steel plates page.

Table of Contents

What Is ASTM A588 Grade A?
Specification
Chemical Composition (Gr A, B, C)
Mechanical Properties
A588 vs A242 vs A709-50W vs S355J2W
Applications
FAQs

What Is ASTM A588 Grade A?

ASTM A588 / A588M covers high-strength low-alloy structural steel shapes, plates and bars with atmospheric corrosion resistance and a minimum yield of 345 MPa (50 ksi) in thicknesses up to 100 mm. It is intended mainly for welded bridges and buildings, where the steel can often be left unpainted. The standard lists several chemistry grades (A, B, C and K) that reach the same properties. Grade A is the most widely produced.

In the open air, the copper, chromium, nickel and silicon in A588 form a tight protective patina after repeated wetting and drying, much slower to corrode than plain carbon steel. A588 is not stainless steel. It is not intended for marine immersion, coastal splash zones, buried use, chemical plants or surfaces that stay wet.

ASTM A588 Grade A Corten B weathering steel plates

ASTM A588 Chemical Composition (Heat Analysis, %)

Grade	C	Mn	P	S	Si	Ni	Cr	Cu	V
Grade A	0.19 max	0.80–1.25	0.04 max	0.05 max	0.30–0.65	0.40 max	0.40–0.65	0.25–0.40	0.02–0.10
Grade B	0.20 max	0.75–1.35	0.04 max	0.05 max	0.15–0.50	0.50 max	0.40–0.70	0.20–0.40	0.01–0.10
Grade C	0.15 max	0.80–1.35	0.04 max	0.05 max	0.15–0.40	0.25–0.50	0.30–0.50	0.20–0.50	–

Grade K (with Mo and Nb) is also listed in the standard. Check the current ASTM A588 / A588M edition and the mill certificate for governing values.

ASTM A588 Mechanical Properties (Plates)

Plate Thickness	Min Yield	Min Tensile	Min Elongation
Up to 100 mm (4")	345 MPa (50 ksi)	485 MPa (70 ksi)	21% in 50 mm; 18% in 200 mm
Over 100 to 125 mm (4–5")	315 MPa (46 ksi)	460 MPa (67 ksi)	21% in 50 mm; 18% in 200 mm
Over 125 to 200 mm (5–8")	290 MPa (42 ksi)	435 MPa (63 ksi)	21% in 50 mm; 18% in 200 mm

A588 has no standard Charpy impact requirement; it can be ordered as a supplementary requirement. For bridges, ASTM A709 Grade 50W (with specified toughness) is normally used.

A588 vs A242 vs A709-50W vs S355J2W

Point	ASTM A588 Gr A	ASTM A242	ASTM A709 Gr 50W	EN S355J2W
Corten type	Corten B	Corten A	Corten B (bridge)	Corten B
Phosphorus	0.04% max	Up to 0.15%	0.04% max	0.030% max
Min yield, thin plate	345 MPa	345 MPa	345 MPa	355 MPa
Max plate thickness	200 mm	100 mm	100 mm	150 mm
Impact test	Supplementary	Supplementary	Required (zone-based)	27 J at −20 °C

Need ASTM A588 plates? Send the grade, thickness, plate size or cut sizes, quantity and delivery location to kamlesh@dineshtube-india.com or call +91 83559 10913. You can also send an enquiry.

ASTM A588 Plate Applications

Road, rail and pedestrian bridges
Building frames and exposed structural steel
Transmission, telecom and lighting towers
Chimneys, stacks and flue ducts
Rail cars, hopper wagons and containers
Retaining walls, noise barriers and landscape steel
Sculptures and Corten signage

Bridge, tower and rail uses of ASTM A588 weathering steel

For Corten tubes, see Corten steel pipes and tubes and ASTM A588 tubes.

ASTM A588 Gr A Plates: FAQs

What is ASTM A588 Grade A?

ASTM A588 Grade A is a high-strength low-alloy structural weathering steel with a minimum yield of 345 MPa (50 ksi) up to 100 mm thickness. It contains copper, chromium, nickel, silicon and vanadium, forms a protective patina outdoors and is the standard US grade behind Corten B.

Is ASTM A588 the same as Corten B?

It is the closest standard equivalent. Corten B is a trade name; ASTM A588 Grade A is the specification that Corten B-type steel is produced to in the US system. The European equivalent is S355J2W.

What is the difference between A588 Grade A and Grade B?

Both have the same strength and corrosion requirements; they differ only in chemistry ranges, so each mill can reach the properties with its own process. Grade A is the most widely produced. Specify the grade only if your drawing requires it.

What is the difference between ASTM A588 and A242?

A588 (Corten B type) has low phosphorus with vanadium and is made in plates up to 200 mm, so it suits thick welded structures. A242 (Corten A type) has higher phosphorus, is limited to 100 mm and is best for thinner plate and sheet.

What is the yield strength of ASTM A588?

Minimum yield is 345 MPa (50 ksi) up to 100 mm, 315 MPa (46 ksi) over 100–125 mm and 290 MPa (42 ksi) over 125–200 mm. Minimum tensile strength is 485, 460 and 435 MPa for the same ranges.

Is ASTM A588 used for bridges?

Yes, A588 is widely used for weathering steel bridges. For new bridge work in the US, the bridge-steel standard ASTM A709 Grade 50W, which adds toughness requirements, is normally specified; its chemistry is based on A588.

Can ASTM A588 be welded?

Yes. A588 welds well with normal structural practice and suitable preheat for the thickness. Where the weld must weather like the plate, use consumables with matching weathering chemistry, such as nickel-copper bearing electrodes.

Which certificates come with ASTM A588 plates?

Every supply comes with an EN 10204 3.1 mill test certificate showing heat number, chemical analysis and tensile results to ASTM A588. EN 10204 3.2 certificates, supplementary Charpy tests and third-party inspection can be arranged on request.

Export Destinations for ASTM A588 Plates

We supply ASTM A588 plates across India and export to the Middle East (UAE, Saudi Arabia, Qatar, Oman, Kuwait, Bahrain), Africa (Egypt, Nigeria, Kenya, South Africa), South and South-East Asia (Sri Lanka, Bangladesh, Nepal, Singapore, Malaysia, Vietnam) and the Americas on request.