Steel Division

Nickel plates

A 645 Gr A / A 645 Gr B, cost reduction and increased safety in ethylene and LNG tank construction

Revision of API Standard 620, "Design and Construction of Large, Welded, Low-Pressure Storage Tanks" in 2018 has made it possible to use ASTM steel grades A 645 Gr A and Gr B for the construction of ethylene, LPG or LNG tanks.

State-of-the-art production facilities make it possible for us to manufacture both steel grades A 645 Gr A and Gr B as well as conventional 5% and 9% nickel steels.

Use of A 645 Gr A for the production of ethylene tanks provides roughly 15% higher strength, increased safety and the possibility of reduced wall thickness for substantial cost savings in tank construction.

ASTM A 645 Gr B achieves material properties equivalent to those of traditional 9% nickel steels in LNG storage but meets these requirements with roughly 30% lower nickel content. A further result is substantially reduced costs in the production of onshore and offshore LNG tanks and in the construction of LNG fuel tanks. 


Natural gas is liquefied at the extremely low temperature of -164 °C, shrinking its volume by a factor of 600. This makes its storage and transport possible and economically efficient. At these very low temperatures, the utilization of special 9% nickel steels is necessary in order to guarantee sufficient ductility and resistance to brittle cracking. We supply extra wide plates to this market segment, even in thicknesses up to 5 mm.


The LPG process is used to produce propane and process gases from natural gas. These gases are liquefied at room temperature at low pressure and are stored in special tanks made of 5% nickel steels. We supply shell plates, heads and cones from a single source.

Highest quality for the highest degree of security

The basis of our high-quality nickel plates are high-purity slabs from our own steelmaking plant. The very low carbon content guarantees perfect weldability. Further advantages are found in the product's excellent impact strength and the fracturing properties (CTOD). The entire plate surface undergoes ultrasonic testing. The residual magnetism is below 50 Gauss.

Preprocessing to meet specific customer requirements

  • Sand-blasted or sand-blasted and primed
  • Preparation of welded edges: Minimal hardening of the burned edge is made possible by the low carbon content.
  • Plate bending

Steel grades

Steel groupSteel grade standardSteel grades
5% nickel steelsEN 10028-4 / ASTM/ASME 645X12Ni5 A/SA 645 Grade A
5.5 % nickel steelsASTM/ASME 645A/SA 645 Grade B
9 % nickel steelsEN 10028-4 / ASTM/ASME 553X7Ni9 A/SA 553 Type 1



Plate thickness:

5 % nickel steels: 5–70 mm (A 645 Gr A 5-50 mm)

5.5% nickel steels: 5-50mm

9% nickel steels: 5-60 mm
Plate width1600–3800 mm, extra wide plates: 9% nickel steels in 5 mm thickness are available in widths up to 2800 mm.
Plate length12,700 mm max.
Ordered weightAt least 2 tons per line item
Unit weight13.0 tons max. per single plate

*) Additional dimensions upon request.


Our product quality is certified by all of the leading certification institutions. We also meet the highest requirements of KOGAS, the state-operated Korean gas company.

Certifications for 5% nickel steels

  • Lloyd's Register of Shipping (LRS), Great Britain
  • Technischer Überwachungsverein (TÜV), Germany
  • Germanischer Lloyd (GL), Germany
  • Registro Italiano Navale (RINA), Italy
  • Lloyd's Register of Shipping (LRS), Great Britain
  • Bureau Veritas (BV), France

Certifications for 9 % nickel steels

  • Lloyd's Register of Shipping (LRS), Great Britain
  • Technischer Überwachungsverein (TÜV), Germany

Contact Person



Heavy plates with a fine microstructure to the very core, created for extremely high toughness and the most adverse environments.

Go to Website