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I am specifying a product made in Australia, which is made of "Grade 520 Steel." The manufacturer of the product lists a minimum yield stress of 520 N/mm² (75,400 psi) and a minimum ultimate stress of 650 N/mm² (94,300 psi) with a minimum elongation of 20% and Young's modulus of 205 kN/mm² (29,700 ksi.) They describe the steel as "A fine grain micro alloyed carbon steel which is fully weldable." The raw steel form should be solid round bar.

My problem is that the plan checker wants a reference to a normative documents (ISO, EN, ASTM spec, etc.) for the material grade. I cannot find who (if anyone) defines this grade of steel. What is the standard organization and standard number that would govern this material?

I have, of course contacted the manufacturer, but what's above is all that they've been able to tell me so far. The only material specification '520' I've been able to find is a withdrawn ASTM tube spec. This component is significantly over-designed, so I'm not concerned with the actual properties, just finding the appropriate document. There are other products available made with ASTM materials, but for visual reasons we'd prefer the Australian product.

Ethan48
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I saw some material for tension rods that match the material properties that you gave, but these places do not list the steel used. It might be proprietary:

A third manufacturer Macalloy, has a similar component that also doesn't list a material specification, but it does have an independent certification of its material properties. This leads me to believe that this is a custom steel that is only guaranteed by its given properties and the agreements between the company and the foundry.

hazzey
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ASTM A615 appears to standardize rebar using that grading designation: i.e. Grade 520 [MPa] (or Grade 75 [ksi]), but only provides testing to ensure that a particular material is at least some strength. The test does not specify composition, only that the material is plain carbon-steel.

BSEN10149 is a British standard grading for steel alloys evidently, and some grades together with mechanical properties are noted on a commercial site, though none of the grades meet the properties you are looking for.

The American Society for Metals has a useful article on HSLA steel grades and associated ASTM standards, but none appear to be for bar material with the required yield strength, though they may be relevant if you intend to do your own testing and verification.

The Society of Automotive Engineers has an article on a grade 980X which according to [Wikipedia] has the required strength but not elongation at failure, and is not in bar form. There is also no associated testing standard that I can see. There may be one in the article but I do not have access.

It is possible this alloy has no current standard, in which case it is highly recommended you verify the properties of the alloy for yourself. Vendor data is often fudged optimistically. Materials of a given category, such as microalloyed steels, always trade off strength for ductility, and the alloy you describe is above the tradeoff curve for all of the microalloyed steels I've seen in my brief search for this answer. That doesn't mean such an alloy doesn't exist, but it would make me cautious. Either the alloy is a new development that is specially made by this vendor, or they are erring optimistically in their marketing. In either case you should consider verifying the properties, prior to putting the materials in service, using the closest applicable testing standard available.

Edit: this answer is attempting to give the OP starting points. Unfortunately I don't have a single answer. Perhaps if the OP obtains their own answer from the vendor at some later time, they could post and accept it.

do-the-thing-please
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