sheetmetal differences?

[metaboman]

I'm after some sheetmetal 1mm thick. I'm looking at a Midalia Steel catalogue and I see there is a variety of sheetmetal types. Could someone tell me the difference between:

Galvanised sheet
Cold rolled sheet
Zincanneal sheet
Zincseal sheet

All of them are available 1mm thick. Is the difference just in the rust prevention/ galvanising properties or are some made of "harder" steel? And do they all handle (cut, braze,fold etc) the same or is that different as well?
Thanks all
Met

[Grahame Collins]

From my limited experience with sheet products.

Galvanised sheet Shiny Silvery material bloodydifficult to mark out cos its shiny and silvery.Gal coating flakes of on a safe edge 180 bend.Crap to weld or braze nasty toxic smoke
Cold rolled sheet Black steel uncoated welds of - bends ok no rust resistance uncoated.Cold rolled steel generally is a bit stronger than hot rolled re mechanical properties.
Zincanneal sheet Rolls and bends well can be welded or brazed with the nasties coming off it
Zincseal sheet pass on that one not familiar with it. might have to Google that one

Perhaps we may be able to offer better advice if we knew what your application was?



Grahame

[Grahame Collins]

ZINCANNEAL® GALVANNEAL ZINCSEAL® and ELECTROGAL are Zinc/Zinc-Iron coated products with traditonaly a matt type surface finish.
These types of coatings are used in products requiring minimal corrosion protection and are usually on interior type applications.

Typical applications include automotive components,office furniture, lighting components and bodies, door and window frames, mounting brackets for computer components and general manufacturing.

Avaialble in different grades and coating weights.

Refer to the Produt Data Manual under the Resources and Tools for the correct application.


EASY

Grahame

[Barry_White]

I'm after some sheetmetal 1mm thick. I'm looking at a Midalia Steel catalogue and I see there is a variety of sheetmetal types. Could someone tell me the difference between:

Galvanised sheet
Cold rolled sheet
Zincanneal sheet
Zincseal sheet

All of them are available 1mm thick. Is the difference just in the rust prevention/ galvanising properties or are some made of "harder" steel? And do they all handle (cut, braze,fold etc) the same or is that different as well?
Thanks all
Met

Met

Most coated steels are cold rolled steels as the give a supeior smoothness to hot rolled steel and can be rolled to better tolerances but cold rolled steel also comes as black steel.

Galvanised Sheet is cold rolled steel but is Hot Dipped zinc coating and it has by far the superior rust protection.

Zincanneal and Zincseal sheet is a electro-zinc coated and is mainly used for things that are to be say paint finished and gives a superior adhesion to the paint and only provides protection whilst in transit and storage and will deteriate very quickly when exposed to the elements.

All these steels come in various coating classes and can vary from Z100 to Z600 which is a not so much a coating thickness but a calculation factor with Z600 being the heaviest coating with the normal beinf about Z275.

The other factor you have is the hardness and the normal is G300 which is basically mild steel which is used in most manufacturing processes because it bends easier etc. and you then have high tensile steel which can be G450 to G550 which what they make steel purlins from and most roofing materials are high tensile except what is called Blue Orb which curving grade roofing which is G300.

Just another point you will find galvanised steels will spit at you whilst you are welding it and is usually better welded with a mig welder and you need to do it in a ventilated area because of the fumes it gives off.

[Barry_White]

Hi Grahame

You got the jump on me. I had two telephone calls while I was trying to write the post whilst reading an old Steel Sheet Fabrication Handbook from BHP Coated Products Division.

[Grahame Collins]

Hi Bazza
My experience is pretty much limited to gal and Zinc anneal here at school for tool boxes and the like.

I don't like gal at all as I said cos its such as pain to mark out on as it's so reflective. Also when folder bits of the stuff flakes off and manages to find a way under ones finger nail.We use the .4mm stuff.

The zinc anneal is much better as it marks out beautifully and takes a nice paint job.

Some of our students have done really good looking toolboxes with Zinc anneal in .6mm.

With a few of us working on segmented folders i suppose there will be a few threads on products made with the said folder.

Grahame

[Wood Butcher]

I have to disagree that welding Gal coated is easier with MIG. In my experience the amount of fumes given off by the gal coating interferes with the shielding gas leading to the risk of porous welds. I find it substantially easier to welding gal coated steel with ARC.

[Barry_White]

I have to disagree that welding Gal coated is easier with MIG. In my experience the amount of fumes given off by the gal coating interferes with the shielding gas leading to the risk of porous welds. I find it substantially easier to welding gal coated steel with ARC.

Hi Wood Butcher

I suppose we will have to agree to disagree but in my experience I've found it easier to weld with mig. When we used to weld galvanised steel building frame with mig we used a fan to blow the fumes away but you had to be careful that the shielding gas wasn't blown away also.

[Wood Butcher]

Barry, if I was welding a house frame then I would use mig too more so due to the thickness of the steel. I'm more used to welding heavy structural stuff and the gal coated steel is a pain with mig.

So different scenarios but at least we agree on one thing - the fumes are toxic.

[metaboman]

OK, thanks for the in-depth information Graeme and Barry. It's all clear to me now.
Cheers
Met

[Peter57]

Barry is mostly correct about the products except that electrogalvanised product is no longer made in Australia.
Here's the rub according to my copy of the Lysaght referee (31st edition 2005 :D ):

Cold rolled is simply thin steel sheet. It is rolled at temperatures lower than red hot (hence the name cold rolled - still gets to about 500C !) and is made from hot rolled steel. Cold Rolled steel as manufactured is actually very brittle and pretty useless. Cold rolled is usually annealed (so technically it is Cold Rolled Annealed steel) before it is sold in coil form to processing centres. It has no corrosion protection apart from a little oil.

Galvanized is coated with zinc in a hot dip galvanising process. This is done at some pretty impressive speeds (ever seen steel strip about a metre wide travelling at 150m/min? It's impressive). Galvanising provides a corrosion protection layer that slows rust down significantly. The problem is that when welding galvanized there are some precautions that need to be taken to reduce exposure to the zinc fumes. One thing though, galvanised solders really easily.

ZINCANNEAL(R) steel is a product made by BlueScope Steel and the ZINCANNEAL trademark is a BlueScope Steel trademark. It is a variant of galvanised steel where the strip is still galvanised by the conventional hot dip galvanising process. Straight after galvanising the product is specially heat treated to make an iron/zinc alloy at the surface of the steel. The generic process is called galvannealing. Galvanneal is used a lot in automotive body panels - that's why they don't rust as much these days. It's reasonable corrosion restistant.

ZINCSEAL(R) steel is another BlueScope Steel trademark and refers to a product that is made in a similar manner to ZINCANNEAL steel but with a lower zinc coating mass to begin with.

So, the choice will depend upon what you want to do with the product. If you want high corrosion resistance then go for galvanised, it has more zinc and that means better performance in cosrrosive environments.
If you want something that's easily shaped with moderate corrosion resistance go for either ZINCANNEAL steel or ZINCSEAL steel.

Cold rolled annealed is cheap, easy to form and weld but has very little corrosion resistance.

Last thing is the grade information:
Hard iron is also called G550 - it's strong but not easy to shape, particularly at 1mm.
Soft iron G300 is much easier to shape. This is the grade things like flashing, etc are made from.
The ZINCANNEAL and ZINCSEAL products are available in even softer grades (G2N) which is dead easy to shape and deform).

How do I know all of this? I work for BlueScope Steel in a technical capacity.

Of course the views expressed are my own and not that of my employer.

If you want some more detailed technical info I'd suggest you call BlueSope's steel direct (1800 800 789) and ask for the technical blurbs.

Cheers,
Peter

[annie wilson]

Cold-rolled steel can be used as such (e.g. in machine components), but is often coated to produce zinc coated sheet or tin plate.

[Dave J]

I am not sure if some members will still be around to see your answer, because this thread was from back in 2007.

Dave

[BobL]

I am not sure if some members will still be around to see your answer, because this thread was from back in 2007.

Dave

Dave I reckon Annie is a software robot.
See this (http://www.woodworkforums.com/f11/dust-collection-systems-141877/#post1446757).

[Dave J]

Ah I see, so I am talking to a robot,:doh: I knew the world would become like this one day, LOL

Dave

[BobL]

Ah I see, so I am talking to a robot,:doh: I knew the world would become like this one day, LOL

Dave

Don't worry I spent half an hour framing what I thought was a well crafted response to a post to "it" on the US site. Still wiping the egg off my face :D
Can be any worse than talking to the dawg!

[Dave J]

Well at least now you know your not alone, now where is that towel,LOL

Dave