Hello Al, I considered his reference to ESAB coreshield 8 and made the mistake of going along those lines. My Bad. I believe that the OP needs to include a lot more information about this question in order to receive the information that he is looking for.
Regardless, qualification with the NR 212 will not suffice for the testing requirements of D1.1 wire classification interchangeability if they plan to run a T8 wire or will it? Am I the one who is wrong? Best regards, Allan
Ya it's me again Al, I am a bit confused as well, I guess. When I looked up the NR 212 it is listed with an AWS E71TG-G designation. So I went about trying to nail down what the G-G portion of the designation was representative of, kind of an odd ball.
I don't have a copy of D1.1 with me right now so I tried to check some information through WABO Standard 27-13 as it is essentially nearly a direct copy of AWS D1.1. Where the T designations are discussed regarding fillers it omits the use of T-2,3,10, and GS, but no mention of G-G anywhere, not even in the acceptable categories. So I guess I would like to be enlightened as well. Thank you and best regards, Allan
the American Welding Society (AWS) classification of Innershield® NR-212 (E71TG-G). While the "G" in FCAW-G stands for gas shielded (or the “S” in FCAW-S for self-shielded), the "G" in a specific electrode AWS classification stands for “general”. Therefore, an E71TG-G classification does not mean that it is a gas-shielded electrode. Typically, a U.S. welding electrode manufacturer (such as Lincoln Electric, etc.) designs an electrode to meet the requirements of a specific, predefined AWS electrode classification, per the appropriate AWS Filler Metal Specification (such as E71T-1, E71T-8, E7018, ER70S-6, etc.). However, a manufacturer is still free to make a particular electrode that does not meet any predefined AWS classification. In these cases, it is classified as "general". Such is the case with Innershield® NR-212, in which the first "G" in the electrode’s AWS number means it has a general usability classification. Innershield® NR-212 also happens to be a low-alloy electrode (i.e. under AWS A5.29 Filler Metal Specification). These electrodes have alloy designations in their suffix (i.e. E71T8-K6, E81T1-K2, E81T1-Ni1, etc.). In the case of Innershield® NR-212, the second “G” is a general alloy suffix classification. Therefore, E71TG-G is its classification.
THE ABOVE INFORMATION IS FROM LINCOLN ELECTRIC TECHNICAL and in part has led to "MY" confusion.
My understanding of the letter "G" in place of the 1, 2, 3, 4, etc. in the classification E71T-G means that it simply has not been approve as meeting an AWS classification. As such, it would not be prequalified.
A welder is still qualified to weld with FCAW electrode under D1.1, but the WPS that required the use of NR-212 (E71T-G) is not prequalified and would have to be supported by a PQR qualified in accordance with clause 4.
As for the classification; E71T-1M JH4
E - electrode
7 - 70 ksi UTS
1 - all position
T - tubular electrode
1 - usability group
M - mixed gas
J - meets impact properties
H4 - meet 4 ml[diffusible H] per 100 grams of weld deposit
The letter "G" you are referring to would be located as such: E71T-GM JH4 (if there were such an electrode)
I think we're on the same train of thought.
This information isn't listed in AWS D1.1. You have to go to the filler metal specification, in this case A5.20 which is now changed to A5.36:2014 if I remember correctly. In a couple of years (2 years if I remember correctly, A5.20 and A5.28 are going away).
Best regards - Al
Thank you Al, obviously the OP needs to chime in here and give "the rest of the story". Once he has clarified this maybe I can overcome some of my confusion. As to the E71TG-G the Lincoln website that I pulled the quote from did give the explanation of what both of the "G's" referred to, one referencing "general" with regard to replacement of a number in the designation of general usability classification and the second "G" is a general alloy suffix classification. Definitely not in my "common" knowledge category. I'll be waiting to see how this plays out. Best regards, Allan
A few years back we had a similar question in this forum and I chimed in that some manufacturers of electrodes used the 'G' to mean gasless. Boy did I open a can of worms. Bottom line is there is a big difference, as has been mentioned, from what AWS requires for marking, what manufactures can use for some descriptions and 'model' identifiers separate from the actual classification of the electrode, and how suppliers, welders, and inspectors describe a particular electrode.
But, once again, we do indeed need much more information than currently at our disposal to form intelligent opinions, comments and responses to the OP.
Possible typos can also make life interesting as well. And we just don't know at this point.
He Is In Control, Have a Great Day, Brent
I saw that e71tg-g on the Lincoln site too. Doesn't make sense. I believe it is a typo and was supposed to be e71t-g.
After more looking at the Lincoln website, I doubt it is a typo. I am not familiar with any differences that may be used in the AWS numbering system for low alloy FCAW electrodes as opposed to mild steel FCAW electrodes. I see I have more to learn on this.
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