Confusion betwen SAE Steel Specs (J series) 1

[jmarkus]

At out company, we usually specify SAE J403 as the reference spec for mild steels and SAE J2340 for HSLA steels. The problem I see, is that J403 is a chemical compostion spec and the equivalent spec for alloy steels would be J404. Similarily J2340 is mechanical (mostly) and J2329 would be equivalent for low carbon steels.

But each of these (J403 vs J2329, or J404 vs J2340) appear to refer to different grades (different grade systems, even).

When we choose materials for our designs, it is usually based on mechanical properties such as yield strength and UTS, not chemical composition.

We use sheet steel and coil steel, and I learned that until recently we were using mechanical properties from J1397 which is a bar stock spec.

To make things worse, we also use steel HREW tubing, and SAE doesn't even have a spec for that so we ask for HREW SAE J-something, but I think the tube mills all use ASTM for there specs!!!!!

How do I straighten this all out!!!???

Thanks,
Jeff

 

[NickE]

I used to work in the low alloy/low carbon industry that you speak of.. good luck rarely will any of the secondary steel suppliers/service centers have updated spec books.. that might help if you can take your spec and get a copy to your supplier.. I also am a proponent of getting certified lab tests (chemistry 12+element, Yeild, Tensile, Elongation, R-Value, n-value, etc...) of each mastercoil.

The specs for steel are annoying, a yar and a half ago a customer ordered steel and told the salesman they wanted 1010... well they ment Steel to ASTM A1010-00 Spec which is similar to J403 (covers all the CR steels IIRC) wow what a mess.

again good luck!

nick


Nick
I love materials science!

 

[TVP]

First, let's tackle the standards issue with J403, J404, J2329, and J2340. As you know J403 & J404 cover standard SAE designation steel grades. J2329 and J2340 are totally different standards, and should not be compared with J403 & J404. J2329 specifically deals with low carbon sheet steels, with compositions that are roughly equivalent to SAE grades 1006, 1008, and 1010. J2340 specifies a range of high strength steels, none of which have standard, J404 type designations. HSLA (high strength low alloy) and DP (dual phase) steels do not have standard SAE-type numbers (e.g. 1020, 4130, 5160, 9310, etc.).

Next, do not use SAE J1397 for estimating mechanical properties of sheet steel grades. As you know, this standard is for steel bars, and therefore not appropriate for sheet steels. Unfortunately, there is no equivalent SAE guide for mechanical properties of flat rolled steels. The best place to obtain this information is from the steel supplier, but handbooks like ASM HANDBOOK Volume 1 or Automotive Steel Design Manual (

http://www.a-sp.org/database/default.asp?doc=28)

also have some data.

And lastly, SAE does have some tubing standards (J525, etc.) but they do not cover the entire range of tubing available. ASTM standards are used most frequently by tube manufacturers, and they reference SAE grades like 1010, 1020, etc. ASTM A 512, 513, and 519 are just a few that cover steel tubes. I recommend you investigate these standards further (tolerances, mechanical property requirements, testing requirements, etc.).

I hope this was somewhat useful. Feel free to post again if you have additional questions.

 

[DR60]

Does anyone know what the chemical composition of SAE J2340 steel is?

 

[TVP]

As I mentioned previously, SAE J2340 covers a range of high-strength steels:

Dent Resistant Non-Bake-Hardenable
Dent Resistant Bake-Hardenable
High Strength Solution Strengthened
High Strength Low Alloy
High Strength Recovery Annealed
Ultra High Strength Dual Phase
Ultra High Strength Low Carbon Martensite

Each one of these categories has requirements for chemical composition and mechanical properties. If you have a question about a specific grade, feel free to post again. If you need the entire standard, you can obtain it from the SAE website:

http://www.sae.org

 

[winergy]

Due to commercial availability and lower cost, our supplier recommends switching the sheet metal grades (hot rolled pickled and oiled) to ASTM A1011 CS type B from SAE 1010. It appears that the mechanical properties are similar, although I am unable to confirm this with the SAE spec (J403?). We have been using SAE 1010 HR sheet for many years. Is switching to the commercial steel specs from ASTM an industry trend? Are their significant differences I should be informed about?

Thanks,
Gary

 

[TVP]

SAE J403 only covers chemical compositions of carbon steels. It is not a product standard, and therefore does not describe mechanical properties, tolerances, product form (sheet, strip, etc.). ASTM A 1011 IS a product standard, and therefore is a more appropriate method for specifying the requirements for steel sheet.

Regarding compositions, CS Type B has more variability than SAE 1010. The carbon content of the former can be 0.02-0.15 vs. 0.08-0.13 for the latter. Also, the Mn content of CS Type B is listed as a maximum of 0.60 instead of a range of 0.30-0.60 for 1010. Wider variations in chemical composition will allow for more variation in mechanical properties and formability. If this is a concern for your application, then you should do some further investigation such as reviewing historical data on the 1010, possibly performing formability analysis on your parts, and definitely discuss potential variation with your stamping supplier.