Properly Specifying and Referencing a Material Standard 1

[ASIT859]

Hi there,
Apologies if I'm being dense on this topic, but I can't quite sort this out.

I'm having some trouble understanding how to properly specify carbon steel plate/sheet materials for fabrication (located in the US). I feel as though I can properly specify an austenitic steel plate - but my understanding of the ASTM standards breaks down when I start to look at carbon steel plates.

As an example, for one application (a pressure containing component) I can specify SS30403 per ASTM A240. I believe this is a complete material requirement. ASTM A240 gives me chemical composition and mechanical properties for the material. It also references ASTM A480 which gives me dimensional tolerances among many other things.

As a problematic example, I'd like to specify a carbon steel for a relatively simple welded assembly which acts as a pump/motor mount. There are many carbon steel options available such as ASTM A36 or perhaps a 1020 steel. I simply cannot interpret the ASTM standards to produce what I think is a complete call out. The material thicknesses in this assembly range from .125 to .250 inches.

A36 provides chemical composition and mechanical properties, and does reference ASTM A6 which provides dimensional tolerances. I believe A36 is a complete material call out - but it's an as-rolled product with dimensional tolerances and surface finish to match.

If I'm interested in specifying a 1020 steel - here is where I have trouble, specifically with cold-rolled.

An as-rolled 1020, I think, could be called out as 1020 AR per ASTM A830. A830 references A6 so I'm good with chemical and dimensional properties, but I don't know where I can find mechanical properties for 1020 AR.

If I wanted to use a cold rolled 1020 b/c of better dimensional tolerances and a nicer surface finish, I don't think I can specify per ASTM A830 since there's no mention of a cold-rolled condition. ASTM A108 looks promising, but it is listed for steel bars - whereas I believe my dimensions are either sheet or plate. Additionally, there's no mechanical or chemical properties listed in A108.

How does one properly specify a cold-rolled 1020 sheet/plate per ASTM standards? I'm sure I can simply list only "1020 CRS" - but what standard do I review to understand what the dimensional tolerances and mechanical properties are of this material?

Thank you

 

[XL83NL]

SS30403 should be UNS S30403.

If you’re concerned about materials only (and not dimensions or geometrical details), then all details that you need to specify will be outlined in the applicable ASTM spec.

It seems, though I’m not overly familiar with CS plate specs under ASTM, you’d be better specifying a different ASTM spec.

Huub
- You never get what you expect, you only get what you inspect.

 

[ASIT859]

@XL83NL,

Thank you for pointing out the error in my UNS S30403 callout example.

Based on your feedback regarding the CS plate spec - I agree. The trouble for me is I don't quite know how to find the appropriate ASTM spec. I'm most often just searching keywords online or on the ASTM site - is there some other way to browse/search material specs that I may be missing?

Additionally - I enjoy and appreciate your signature - very true.

Thank you

 

[XL83NL]

Understand your point. It’s not only about knowing which ones there are, you also need to know which ones are often used and are readily available.
What’s your background? Any resources like the stahlschlussel that you may have already tried consulting?

Huub
- You never get what you expect, you only get what you inspect.

 

[3DDave]

I always started with the supplier catalogs for available materials. If you are looking to buy a mill-run then contact the mill.

In terms of on-line searches a search for 1020 cold rolled leads to matweb which lists:

UNS G10200, AMS 5032, AMS 5045, ASTM A29, ASTM A108, ASTM A510, ASTM A519, ASTM A29, A108, A510, A512, A513, A519, A544, A575 M10120, A576, A635, A659, A827, A830, BS 970 040A20, 050A20 (En2C), 050A20 (En2D), 060A20, BS 970 Part 1 070M20, DEF STAN95-1-1 C1020, SAE J412, SAE J414, DIN 1.0402, AFNOR CC 20, UNI C 20, SS14 1450 (Sweden), SAE J403

However, matweb lists no suppliers. So that brings it back to the first line.

Unfortunately I think owning a copy of the ASTM standards is the shortest path to deciding what you want. I had access to 30 or so volumes; it is supposed to be 80 volumes now. The current price for a one-year printed full version is under $15k, but you can save a lot by sticking with the few categories you need - Steel & Ferrous is ~$2k.

See

https://www.astm.org/products-services/bos.html

Just to add - dimensional tolerances depend on the original plate size as rolled by the mill, getting back to having to contact the mill to find out. A similar issue happens with properties as they vary with as-rolled thickness. Intermediaries who cut plate to size may not be able to to any better than tell you what they have on hand.

 

[JStephen]

In the past, I occasionally ran into offers of "commercial quality" steels, perhaps used in trailer manufacturing or something like that. As best I could tell, they simply weren't produced to any particular spec. (Or perhaps they were produced to meet a particular spec, failed to meet it, and were thus being sold off as no-spec materials.) I don't know how common this is/was.

Anyway, if you have suppliers you routinely work with, you might do better to see what's readily available with them, and work it from that end. If hot-rolled steel is adequate, A36 would be about as common as anything in the 3//16" to 1/4" range, I'm not sure about below that.

"AR" can also mean abrasion-resistant steels (high strength, high hardness), so be careful how you use the "AR" term.

 

[geesaman.d]

It's quite tricky knowing what materials are commercially available, but especially now, it's crucial.

Find a few steel and stainless suppliers in your region, go to their website, and hopefully they have an indication of which materials they actually stock and what range of sizes.

Sadly, websites are intentionally optimistic about their stock materials and most suppliers stocking plans have been shattered since the pandemic. So if it's critical to use in-stock material, I'd make a phone call or two to confirm the metal is around. Good example, my company occasionally made shafts from Sch80 pipe in 10" and larger sizes. We recently found it's not being produced anymore without a mill run. We adjusted our design methodology to use SchXS, which is better stocked. I see you're considering 304L S/S - in my recent experience, it's the same price as 316L but 316L is less lead time, and in my world 316L is almost always an upgrade.

If you're not getting good response from a random metal supplier (after all, they may be barely able to help their paying customer base), get the name of your largest fab shop's metal supplier. Then try to be polite and quick.

As for using the ASTM standards for material callouts, I only ever call out the higher level standard which is usually the one with the material composition definition. A-36, A895, A516. The various tolerance standards and testing definition standards are automatically pulled in. For some grades, the standard number is all you need, however some standards specify multiple materials and you need to call that out also. So "CF3M PER ASTM A743" or "ASTM A516-70N" where -70N is grade 70 Normalized.

Also be aware that some standards are based on mechanical properties, chemical properties, and other things. If you buy A-36 there won't be a precise chemistry definition because it's built around a minimum strength. A516 however gives both stregth and chemical composition control. If you buy A-48 Grade 30, there won't be any control on machinability/hardness unless you add one.

 

[Tmoose]

"For some grades, the standard number is all you need, however some standards specify multiple materials and you need to call that out also. So "CF3M PER ASTM A743" or "ASTM A516-70N" where -70N is grade 70 Normalized."

I starred Geesaman's port for that statement.

Just the day before yesterday I spent over an hour trying to conjure up what we probably really meant 11 years ago when ASTM B36 was put on a drawing.

https://cdn.britannica.com/05/9405-...ll-game-Hieronymus-Bosch-Municipal-Museum.jpg

 

[weldstan]

AWS D1.1 provides many commonly used sructural carbon steel materials.

 

[mfgenggear]

it really depends on the quantity of the finished product. go to a raw steel supplier for the targeted material (as geesaman suggested) and look at the stocked material size and specification available in your area. allow alternative material if allowed as well. contact them for lead time and availability. for a small lot this will be important, as a material with a mil run will not be feasible.

 

[EdStainless]

Back one step, understand the structure of ASTM specs.
At the application end there are Product Specification. They sometimes and a size range and suggested application.
They will cover a group of alloys manufactured in limited number of ways, and in a limited group of forms (plate and sheet).
These product specs also contain HT information and mechanical properties (if they are used for ASME applications also).
The product spec will refer to a General Spec. This a much larger group of products (some apply to over 20 product specs) and it lists all of the general requirements. And example would be that it lists how to do all of the destructive and NDT methods, but which are required are called out in the product spec.
The General Spec will also tell you which testing specs (such as tensile and NDT) apply.
If the product spec contains any chemistry or tolerance information then this supersedes other specs in the chain.
For some product forms there are general tolerance specs.
And in product specs there are often Supplemental Requirements, these are commonly ordered options that have been put there to simplify invoking them.

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P.E. Metallurgy, consulting work welcomed

 

[ASIT859]

Hi everyone,

I just wanted to come back around and thank you all for your replies. Each of these was very helpful and I've been leaning on some of these tips over the last several months and will continue to do so going forward. The recommendation of finding out what our suppliers typically had on hand was particularly helpful. I'm sometimes not in control of who we purchase from, but I am aware of our major suppliers so it's at least a great starting point.

Thank you.