Steel Plates & Sheets

Coating pipe,Coated pipe,Pipe fitting
Structural Steel

Structural Steel

Structural Steel

Our materials offer high yield and high strength and can be supplied with numerous finishes and testing options. Please refer to the information below detailing markets which we currently supply steel to with links to grades and technical information.

Part of Masteel’s strength is the ability to be able to provide a total solution for your business, offering added value services including computerised multihead profiling. This means we can cut your structural plate to your exact requirements.

The Construction Industry
High tensile strength and yield strength steels including S235, S275 and S355 with Charpy impact testing at different temperatures.

The Offshore Industry
Offshore structural steel grades for the building of offshore platforms including S355, S420 and S460.

The Shipbuilding Industry
High quality shipbuilding structural plate including AH36, DH36 and EH36 supplied under the ASTM A131/ASME SA131 specification

Predominantly, offshore structures are built specifically for drilling oil and gas deposits deep under the sea bed. Whilst applications will vary, all will have exposure to the effects of salt water corrosion, powerful sea currents often dictated by the tides and strong winds. Our search for natural fuel resources has stretched into even more inaccessible areas such as the Arctic which has also resulted in rigs drilling at much greater depths and hence lower temperatures.

Structures in harsh working environments like these require a specific range of steels to promote greater safety, longer working life and reduce the risk of failure which in certain cases could prove disastrous.

Offshore Steel Characteristics:

High yield strength
Excellent weldability
Good internal soundness
Good resistance to brittle fracture (longitudinal and transverse)
Low phosphorus and sulphur contents
High resistance to lamellar tearing


S355G7 is a structural grade steel supplied to the offshore industry. The material can be delivered as normalised (N) or thermo-mechanically rolled (M). Supplied in accordance with EN10225:2001, the steel offers good tensile and yield strength.

As an offshore steel grade, S355G7 is used in a variety of applications including the building of offshore platforms. Masteel UK Limited can supply the steel from stock or directly from the mill to customer destinations on a global footing. Please refer to the technical information for S355G7.

Mechanical Properties of S355G7

Tensile Strength Nominal Thickness (mm)
Thickness (mm) Elongation A
< 100 >100 <16 >16 <25 >25 <40 >40 <63 >63 <100 >100 <150 %
S355G7+M 470/630 355 355 345 335 325 22
S355G7+N 470/630 460/620 355 355 345 335 325 320 22

Chemical Composition of S355G7

C 0.14
Si 0.15/0.55
Mn 1.00/1.65
P 0.02
S 0.01
Cr 0.25
Mo 0.08
Ni 0.5
Al 0.015/0.055
Cu 0.3
N 0.01

Product Specification

Our hot rolled shipbuilding steel is produced in accordance with the relevant Classification Society, examples of which include Lloyds Register and Det Norske Veritas.

Our steel products include steel shipbuilding plate, fabricated steel sections and floor plate for decking. We can also supply bulb flats for plate stiffening, structural steel angles and inverted angles.

Our plates are supplied under the ASTM/ASME specification (ASTM A131 / ASME SA 131) which is the standard specification for Structural Steel for Ships.

We offer higher strength shipbuilding steels as standard .High strength steels offer significant cost advantages by reducing the weight of the structure in comparison to the steel used. The plates are suitable for use in the construction of container ships and large cargo freighters as well as commercial shipping lines such as luxury cruise ships and ferries.

Supply options include heavy plates, surface treated plates and pre-fabricated sections. In most cases, the steel can also be supplied as hot rolled coils or cut into lengths (sheets).

These high yield materials are commonly used in the construction of hulls and superstructures for large shipping vessels. The grades are exclusively for shipbuilding use as set out in the standard.


We supply grade AH36 high strength structural shipbuilding steel to the ASTM A131: Part 4 specification.

Masteel UK Limited supplies Grade AH36 to the world’s master shipbuilders in accordance with the classification society of your choice. The material can be supplied as heavy plates, surface treated plates and fabricated sections.

The steel is used in the construction of container ships, bulk carriers and commercial ships such as liners and ferries.

Mechanical Properties of AH36

A50mm A200mm
MPa MPa % %
AH36 355 490/620 22 19

Chemical Composition of AH36

C 0.18
Si 0.10/0.50
Mn 0.90/1.60
P 0.035
S 0.035
Cr 0.20
Mo 0.08
Ni 0.40
Cu 0.35
Cb 0.02/0.05
V 0.05/0.10


Masteel UK Limited supplies Grade DH36 to shipbuilders worldwide in accordance with the classification society of your choice and in accordance with ASTM A131:Part 4.

The material is available in heavy plates, surface treated plates and fabricated sections. The shipbuilding structural steel is used for the main structural build including the hull and superstructure. DH36 is suitable for new builds or refits and can be found in large bulk carriers, container ships and passenger liners.

Mechanical Properties of DH36

A50mm A200mm
MPa MPa % %
DH36 355 490/620 22 19

Chemical Composition of DH36

C 0.18
Si 0.10/0.50
Mn 0.90/1.60
P 0.035