[Documentation] Steel designations

Galileu

Galileu

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Hi,

I would really like to understand steel designations because I see you people refer to steel types which don't seem to mean anything in Portugal. What I usually buy is called "C1 steel" and it's listed in the supplier catalogue under construction steels (carbon); it's number 8 on this list http://www.ramada.pt/index.php?cat=45&eb=13. It would be nice to be able to make an equivalence between the designations in this country and the ones you people use. Maybe it could be done referring to international norms, like DIN; at the moment I am unable to decode the numbers I see in your posts.

Any help welcome.
José
 
Galilu,
I will try to wade in and give the readers digest answer. Mild steel is numbered with a 4 digit system. Numbers such as 1018, 4130, 4140 and others. There are a few specialty designations such as A-36 and AR-400 too. The 4 digit system is a standardized numbering system to denote the contents of the steel or alloy. Thus a 4130 has 30 of something, 1 of something and the base metal is a 4. We all know that 4130 is commonly refered to as chrome moly. A misnomer because it is not necessarily stronger, just has a higher tensile and resistance to bending. That is why roll cages are 4130 DOM (Drawn over mandrel). 1018 is just plain old mild steel but has particular properties that must be duplicated by each metal smelting mill. So in a nut shell it is a basic recipe that tells the contents of the material at a glance. Aluminum also has a few different alloys. Some can be tig welded others not so well. The alloy you choose must be suitable for your project. For example 5356 is unsuitable for applications over 150 degrees continously. 4346 or 6061 would be much better for that type of application. If you have a look at Machineries handbook it will give the tensile and elongation numbers of 99% of all common and some exotic metals. I have really simplified the answer to try to save space, but I hope this gives you the gist and an isea where to look for all of the different alloys available.
Bob
 
Hi,

I'm not sure I understand it. So, the "C1 steel" I've been buying has 0.20% carbon, 1.40% molly, 0,045% phosphorous and 0.045 sulfur, what does that make it?

José
 
Hi Tony,

I couldn't find it in that table either but since the composition is known it should be possible to find the equivalent SAE designation. I tried to do it from the rules found in Wikipedia but I couldn't; this is the link: http://en.wikipedia.org/wiki/SAE_steel_grades

José
 
There aren't that many alloys with as much as 1.40% mo. I scanned through the EMJ handbook (great resource, btw) and the closest I could get to what you have, going strictly by the c and mo is AISI 651, which is higher in carbon, so probably not what yo have. It's considered a high temp, high strength alloy with considerable chrome and nickel in it also. Pretty expensive stuff I'd say.

Are you sure it's 1.4% and not .14%? That would fit better in the lower carbon family.
 
Tony,

My mistake; I rechecked and it is 1.4% Manganese and not Molly, just as you said. Those are very helpful links; thank you.

José
 
Tony,

As for the american equivalent to C1, I guess it should be 1520, if I understand correctly the Wikipedia page: http://en.wikipedia.org/wiki/SAE_steel_grades. It is a 15xx, because it is a carbon steel with more than 1% Mn and then it should be 1520 because it has 0.20% C. Am I right?

José
 
Mayhem said:
I'm going to ask a question that I think I asked here before but got lost in the transfer.



Galileu - if you would prefer I start a different thread for this question, please let me know. I don't want to hijack your thread.
Click to expand...

You're welcome!

José
 
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