Shipbuilding steel plate
B
Grade B carries impact testing at 0°C and is specified for primary hull structural members with a general notch-toughness requirement.
Mechanical properties
- Grade class
- Normal strength
- Minimum yield ReH
- 235 MPa
- Tensile strength Rm
- 400–520 MPa
- Elongation A5
- 22%
- Impact test temperature
- 0 °C
Impact energy in joules is not listed here because it varies with plate thickness and specimen orientation. The value that governs your order is the one on the mill test certificate, issued per heat.
Impact toughness for B is verified by Charpy V-notch testing at 0°C, per IACS UR W11.
Definitions of ReH, TMCP and other terms: see the glossaryChemical composition
Ladle analysis limits in weight per cent, as the WISCO mill publishes them for this grade to CCS. Als is acid-soluble aluminium.
| C | Mn | Si | P | S | Als | Nb | V |
|---|---|---|---|---|---|---|---|
| ≤ 0.21 | 0.80 – 1.20 | ≤ 0.35 | ≤ 0.035 | ≤ 0.035 | — | — | — |
These are the mill's published limits for ladle samples. The actual values for your plate are on the mill test certificate, and a classification society can ask for tighter limits.
Stock & dimensions
- Thickness
- 3–22 mm
- Widths
- 1,500 / 1,800 / 2,000 mm
- Lengths
- 6,000 / 8,000 / 10,000 mm
Mill rolling range
Sizes the WISCO mill rolls to order, beyond what is held in stock. Supplied to GB 712 and to the rules of BV, CCS, DNV, GL, LR, KR, NK and RINA, with dimensional tolerance to GB/T 709 and a lower thickness deviation of −0.30 mm. Send the requirement for availability and a lead time.
- Thickness
- 2–25.4 mm
- Widths
- 800–2,100 mm
- Lengths
- 2,000–12,000 mm
Also rolled as coil
- Original coil
- 2–25.4 mm × 800–2,100 mm
- Skin-pass coil
- 2–12.7 mm × 800–2,100 mm
Coil sizes are the ranges in the mill's own product table. Confirm coil availability before you plan around it.
Currently in stock
Classification society approvals
Material is produced at the WISCO mill, which holds works approval from the nine classification societies below. Material is released with the mill test certificate for the relevant heat.
- CCS B
- ABS B
- DNV B
- GL B
- BV B
- LR B
- RINA B
- KR B
- NK B
Standards & cross-reference
This grade is also recognized under ASTM A131/A131M (the U.S. shipbuilding-steel specification) and GB/T 712 (the Chinese national shipbuilding-steel standard), both of which use the same B designation as the IACS classification-society rules.
General structural-steel standards such as EN 10025 (Europe) and JIS G3106 (Japan) lack classification-society approval for ship hulls and cannot replace B on a classed vessel. AH36 vs A36
Quick answers
What is the lead time for B plate from ZCMetals?
B is held in stock in Wuhan — ex-warehouse delivery in 3–7 days from order confirmation.
What certificate ships with B plate?
A mill test certificate (MTC) to EN 10204 3.1, issued per heat, plus a classification society certificate copy for whichever of our nine approved societies your project requires. Independent third-party witnessed inspection (EN 10204 3.2) can be arranged on request.
What is the minimum order quantity for B?
From 1 tonne on sizes already held in stock — bundles are broken to order.
Welding & cutting
Cutting
Both oxy-fuel (flame) and plasma cutting are suitable for this thickness range; cut to your drawing or DXF file.
Welding & preheat
Readily weldable by standard shipyard procedures (SMAW, FCAW, SAW). Preheat is generally not required at typical hull-plate thicknesses, but always follow your yard's approved welding procedure specification (WPS) and classification society requirements for the specific joint and thickness.
Related grades
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