Cor-Ten B weathering steel plate

CORTEN B Steel Plate

Weathering Steel COR-TEN with high tensile strength has overcome rust, which is the weakest point of steel, in a unique manner, by actually using rust. Click here to learn about Cor-Ten A.

When COR-TEN with bare specifications is left in the atmosphere, rust occurs first in the same way as ordinary steel, but dense protective rust forms on the surface of the steel due to the action of the alloy element over time, inhibiting the later development of further rust.

Since COR-TEN B has excellent weather resistance, it can be used without any coating. It provides not only the economic effect of a reduction of re-coating cost, but an aesthetic effect with sedate color of protective rust.

Coating property

  • The coating film has a long life, and the recoating cost can be reduced.


  • Welding is easy using any method of manual welding or submerged arc welding, etc.
  • Spot welding is also possible for thin materials.


  • COR-TEN can be subjected to cold working, hot working, and gas cutting in a similar way as ordinary steel with the same strength level.

COR-TEN B exhibits a yellowish appearance in the initial stage of use, and the color gradually changes to brown. Then, as it sits in its surrounding environment, the color changes to a sedate blackish brown in one to two years. Then, the color changes very little once again, but only to a deep brown.

Weathering steel, best-known under the trademark CORTEN B steel and sometimes written without the hyphen as "CORTEN B steel", is a group of steel alloys which were developed to obviate the need for painting, and form a stable rust-like appearance if exposed to the weather for several years.

Chemical Composition (%) of Corten B Steel
C max Si Mn. P S max Cr Ni Cu V
0.16 0.30-0.50 0.80-1.25 0.030 0.030 0.40-0.65 0.40 0.25-0.40 0.02- 0.10
Mechanical Properties of Corten B Steel
Thickness (mm) Plate Products Yield Strength Tensile Strength Elongation
  Rel N/mm² Rm N/mm² A50 %
Strip Products Minimum Minimum Minimum
2 – 13 6 – 40 345 485 19
Equivalent Grades of Corten B Steel
Material # EN 10155 SEW 087 NFA 35-502 UNI BS 4360 ASTM JIS G3114
1.8961 S235J2W WTSt 37-3 E 24 W 4 Fe 360 DK 1 - - -
1.8945 S355J0WP E 36 WA 3 Fe 510 C1K1 WR 50 A - - -
1.8946 S355J2WP - E 36 WA 4 Fe 510 D1K1 - A 242 Type 1 -
1.8959 S355J0W - E 36 WB 3 Fe 510 C2K1 WR 50 B A 588 – A 242 Gr. 1 SMA 50 AW
1.8963 S355J2G1W WTSt 52-3 - Fe 510 D2K1 WR 50 C A 588 Gr. A to
1.8965 S355J2G2W - - - - - SMA 50 CP
1.8966 S355K2G1W - E 36 WB 4 - - A 709 Gr. 50 W -
1.8967 S355K2G2W - - - - - -
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