Description: BBN steel is a well-known steel manufacturer and service provider in China, ASTM A588 Grade B (A588 Gr50, Corten B)Corrosion Resistant Steel is our superior product, we are favored by customers with high quality, competitive price and excellent service
Payment Terms: L/C, T/T, D/P, Western Union, Paypal, Money Gram
ASTM A588 Grade B (A588 Gr50, Corten B) Corrosion Resistant Steel Plate | Weathering Steel for Bridge, Tank & Tower
Weathering / Atmospheric Corrosion Resisting Steel (A588 Gr B = Corten B) | Forms a Protective Rust-Patina Outdoors | Bridge, Railway, Storage Tank, Wind Tower & Transmission Tower | MTC & Third-Party Inspection
Atmospheric Corrosion ResistanceASTM A588 Grade B builds a dense, self-adhering oxide patina in weather that slows further atmospheric corrosion, eliminating long-term repainting for outdoor structures.
High Strength (Gr50)Grade 50 delivers a minimum yield of 345 MPa (50 ksi) with 485 MPa minimum tensile, higher than mild steel and easily welded with common procedures.
Stock & Fast DeliveryOver 1000 tons of A588 Gr50 plates in stock monthly, covering common thicknesses for Latin American and Middle Eastern projects.
01Product Overview & Specifications
ASTM A588 Grade B (also supplied as A588 Gr50 or traded as Corten B) is a premium atmospheric corrosion resisting structural steel. Its special chemical composition accelerates the formation of a tight, self-adhering protective rust patina when exposed outdoors, eliminating the need for anti-rust painting over long-term service.
A588 Gr50 offers higher yield than plain carbon steel and is readily welded with common procedures, making it ideal for heavy outdoor load-bearing structures such as bridges, storage tanks, railway wagons and wind turbine towers.
Item
Specification
Steel Grade
ASTM A588 Grade B (A588 Gr50 / Corten B) — atmospheric corrosion resisting structural steel
Promptly (Stock) / Custom production: 10 – 40 working days
Stock Status
Over 1000 tons monthly
Certification
Mill Test Certificate (MTC) available, third-party inspection supported
Payment Terms
T/T, L/C At Sight
02Equivalent & Related Weathering Steel Standards
ASTM A588 Grade B is the U.S. standard weathering steel most often traded under the name Corten B. It is commonly cross-referenced with the standards below for engineering substitution; confirm composition limits and certification under the target standard before design-critical use.
Standard System
Equivalent / Related Grade
ASTM (USA)
A588 Grade B / A588 Gr50 (this grade)
Corten (generic / trade)
Corten B
ASTM (USA, older)
A242 Type 1
EN (EU)
S355J2W / S355J0W (EN 10025-5)
JIS (Japan)
SMA490BW / SMA490CP (G 3114)
Note: ASTM A588 Grade B is the standard designation of this weathering steel and is widely known in the market as Corten B. The grades above (ASTM A242, EN 10025-5 S355J2W/S355J0W, JIS G 3114 SMA490BW/CP) are commonly referenced related weathering-steel standards. They share the atmospheric-corrosion-resisting concept but differ in exact composition limits and certification — verify against the ordered specification and Mill Test Certificate (MTC) before use.
03Grade Designation & Meaning
ASTM A588 Grade B (A588 Gr50) — how the designation breaks down.
A588
A588 — ASTM Spec
A = ASTM standard; 588 = the specification number for high-strength low-alloy structural steel with atmospheric corrosion resistance.
Gr50
Gr50 — 50 ksi Yield
Grade 50 means a minimum yield strength of 50 ksi (345 MPa) — the origin of the "Gr50" naming.
B
B — Grade B
Grade B is the higher-strength type of A588 (vs Grade A / Gr50W), with the 345 MPa minimum yield listed above.
Corten B
Corten B — Trade Name
A588 Gr B is the grade most often supplied under the trade name Corten B; both refer to the same atmospheric-corrosion-resisting steel.
A588 Gr50 processing note: A588 Grade B contains more alloying elements (Cu, Cr, Ni, P) than plain carbon steel, so forming is somewhat more difficult; it can be moderately drawn and is easily welded with common procedures (spot, TIG, MIG, MAG, electrode). It is optimized for welded outdoor atmospheric-corrosion-resistant structures where weather exposure and low maintenance matter most.
04Chemical Composition
Chemical composition of ASTM A588 Grade B (A588 Gr50) weathering steel (ladle analysis, %). "Max" denotes maximum allowed.
Element
Composition Range (%)
C (Carbon)
Max 0.20
Mn (Manganese)
0.75 – 1.35
Si (Silicon)
0.15 – 0.50
P (Phosphorus)
Max 0.04
S (Sulfur)
Max 0.05
V (Vanadium)
0.01 – 0.10
Cu (Copper)
0.20 – 0.40
Cr (Chromium)
0.40 – 0.70
Ni (Nickel)
Max 0.50
Note: Copper, chromium, nickel and phosphorus are the key alloying elements that build A588 Gr50's atmospheric-corrosion-resisting patina; phosphorus and sulfur are maximum impurity limits. The exact heat-analysis of each coil/plate is stated in its Mill Test Certificate (MTC).
05Mechanical Properties
Mechanical properties of ASTM A588 Grade B (A588 Gr50) steel plate (minimum values per ASTM A588/A588M).
Note: A588 Grade B is a weathering steel; the values above are minimum requirements per ASTM A588/A588M. Because it contains more alloying elements than plain carbon steel, forming is somewhat more difficult and it can be moderately drawn; it is easily welded with common procedures. Charpy impact testing is available on request and confirmed in the MTC for your required condition.
06Product Types, Processing & Service
BBN Steel keeps over 1000 tons of ASTM A588 Grade B / A588 Gr50 weathering steel plates in stock every month, covering all common thickness specifications for Latin American and Middle Eastern projects. Plates are fully traceable with official Mill Test Certificates — ideal for heavy outdoor load-bearing structures.
1
Weathering Steel Plate
Hot-rolled A588 Gr50 plates in all common thicknesses, customizable fixed length per your drawings.
2
Stock & Traceability
1000+ tons in stock monthly; plates fully traceable, MTC provided upon purchase.
3
Cutting & Processing
Custom cutting, flattening and processing; third-party inspection supported.
1
Fast Delivery
Common sizes shipped promptly from stock; custom production 10–40 working days.
2
MTC & Inspection
Mill Test Certificates available; third-party quality inspection supported.
3
Flexible Payment
T/T and L/C at sight accepted for your convenience.
4
24h Consultation
Professional sales team provides 24-hour online consultation and quotation.
ASTM A588 Grade B (A588 Gr50, Corten B) atmospheric corrosion resisting steel plate
Forms tight self-adhering protective rust patina outdoors — no anti-rust painting for long-term service
For bridges, railway wagons, water storage tanks, ventilation fans, industrial chimneys, boiler supports
For wind turbine towers, oil & gas storage tanks and transmission towers (widely selected in Brazil & Egypt)
Over 1000 tons in monthly stock for Latin American and Middle Eastern projects; MTC & third-party inspection
Get Your ASTM A588 Grade B (Corten B) Quotation Now
Send us your dimensions (thickness × width × length), quantity, and application (e.g. bridge, storage tank or wind tower). We will reply with stock status, competitive factory price and complete certification.
BBN Steel has established a complete set of production and supplier management system processes to ensure the improvement of product quality and better service to users.
Production Control
BBN Steel has established a complete production quality control process to ensure every link from research and development to mass production.
Supplier management
Our supplier selection will consider factors such as health and safety, ethics, environmental protection, price and quality to better serve customers.
Certification & Patent
We have successively won various international authoritative certifications, GB /T19001-ISO9001: 2000 quality management system was implemented.
After sales service
We provide booking space, shipping tracking service and after-sales service, we will always be first-class products and perfect pre-sale and after-sales service.
Get in Touch
Welcome to contact us through online consulting, emails and hotline if you are interested in our company or products. Our staff will reply you within 24 hours.
Address: HIGH-TECH DEVELOPMENT ZONE, ZHENGZHOU, CHINA
