Imported Steel for Sheds?

Posted on : August 20, 2011

This picture was taken only two weeks ago.

For non shed readers, steel manufacturers create hot rolled steel, for sheds they then create cold rolled steel that is consumed by rollformers to create the portal frame for your shed.

At each of these stages there is a chance that steel is imported, the rollforming for custom designed sheds is usually done in Australia as the volume of the kit reduces the economics of importing, the lack of economies of standard colour and sizes and the delivery network make it more economical to do in australia.

Australia has high standards and locally produced Bluescope / Onesteel steel is of an excellent quality meeting all of the Australian standards.  It is very unusual for Australian manufactured steel to crack during roll forming and usually has a very high consistency gauge.  Ask any roll former and they will tell you that the quality of some imports is hopeless, and that it has a greater chance of splitting or causing issues with the machinery due to greater irregularity in steel gauge across the coil.

A growing portion of cold rolled coil is coming from overseas and you will not see made in Australia printed on any coil now days, just “made by manufacturer x”.

The question for the readers is, who was this steel imported from?

To explain the above further – the cold rolling part of the manufacture process starts off initially as cold, but as the material is rolled it is reduced in thickness and also gains heat. The steel at this point changes in mechanical property regarding strength etc, and also usually bathed in oil to prevent rusting if exposed to H2O and O2. This cold rolling gives the steel the mechanical properties required depending on the thickness required for end product use. These coils may also be heated (cold rolled annealed) to make the steel more flexible for folding processes, and the to a coating line to galvanise (coated in zinc) or Zincalume line (zinc-aluminium alloy) with painting (colour) if required. Cold rolled steel is then made available in different grades, properties and coating depending on the end usage. For example the purlin in the above photo is C20015 and is from a G450, Z350 coil. The G450 indicates the minimum yield strength in MPa, and the Z350 is the coating of Zinc – in this case was minimum 175 grams per square meter on the top an bottom of the coil. All these factors can vary depending on use – but what guarantess can be given that the imported coil used has the same strength, properties and coating requirements compared to that of BlueScope Australian made?

Are the coils below imported or Australian made?

Cold Rolled Zinc Coil

 

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One Response to “Imported Steel for Sheds?”

  1. The Roofer said...

    I’ll take a guess that the photo of the split purlin is from BlueScope! May even have been from one of their overseas manufacturing units. Why do they only put “Made by BlueScope” when a more patriotic brand would be:-
    “MADE IN AUSTRALIA BY BLUESCOPE” ???????

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