Suitable materials

  • Most ferrous materials are suitable to be hot dip galvanized, including sound stress-free castings.
  • Non-ferrous materials such as brass, aluminium and copper are not suited to the hot dip galvanizing process. 
  • It is not recommended to galvanize stainless steels.
  • Most hot rolled or cold formed steels, including structural angles, UB’s, UC’s, welded beams, channels, welded CHS, RHS & SHS, reinforcement steels and fastener grade steels can be galvanized. In general, the mechanical properties of structural steels are not affected by the galvanizing process. 
  • High strength steel up to 340HV are also able to be galvanized when acid pickling is not used in the pre-treatment of the steel. 
  • Steel composition (particularly silicon and phosphorus content) can affect the characteristics of the hot dip galvanized coating. 
  • Sulphur-containing free-cutting steels (for example S1214) are normally unsuitable for hot dip galvanizing. 
  • Grey cast iron and malleable cast iron can be galvanized, but special considerations need to be met. For more information, refer to Clauses 2 and 9 of AS/NZS 2312.2.
  • Combinations of ferrous materials or surface conditions

– Fabrications containing a combination of castings and steels, or rusted and mill scaled surfaces may be abrasive blast cleaned before galvanizing to provide a more consistent initial surface finish.

– Weld slags must be removed, which can be done via chipping, grinding, or using a pneumatic needle gun.

  • Brazed assemblies may be galvanized, but check first with your galvanizer.
  • Soft soldered assemblies cannot be galvanized.