When you’re worried about making the wrong choice.
When your spool of flux core wire in your welder has ran out. And you’re standing in your local welder’s supply store.
Or you’re looking on-line.
There’s this wire called E71T-11 and E71T-GS.
And heck they’re even from the same brand.
What’s the difference?
It’s crazy that you don’t know.
And when you don’t want to gamble on a successful weld.
Which do you pick?
E71T-11 Versus E71T-GS What’s The Difference?
Both are flux core wires made for mild steel. The letters and numbers are specs from the American Welding Society. E71T-11 is a wire for all positions and multi-pass welding.
E71T-GS is a general wire. And the maker’s say what it does. Normally it’s for all positions and single pass welding. But you’ll need to check.
Want to look deeper? Read on …
What Do The Numbers E71T On The Welding Wire Mean?
And this code tells you what type of welding wire you’re buying and what the wire can do.
The code can appear on the spool of wire. Or the brand makers often use it as part of the welding wire’s name. This is so that it’s easy for you to see at a glance what you’re buying.
But that’s only helpful if you know what the code means.
And now you’re going to be in the know.
The first letter E means electrode. And this means electricity passes through this wire. And it does all the time you’re welding.
Next is 7. This tells you the strength of the wire. And your wire has a tensile strength up to 70,000 pounds per square inch.
Next up is the number 1. And this says your welding wire is for welding in all positions. You can use this wire when you weld on the flat, horizontal. And for welding vertical and over your head.
The last letter T tells you is a flux cored wire.
But when you’re cautious about buying an E71T 11 welding wire. Compared to an E71T GS what does the last part of the code mean?
Because you don’t want to buy the wrong one.
What Does E71T GS Mean Compared To E71T 11?
The numbers after the dash are “Usability Designators”.
What does that mean?
It tells you what to expect from the wire.
Unveiling What E71T GS Wire Is All About
The letters GS means this is a general classification wire. And it’s for welding single pass.
But the real thing for you to know is that GS flux core wire has few standards to meet.
There’s no testing by AWS on this wire.
Your GS wire meets the standards ‘as agreed between supplier and purchaser’.
What does that really mean?
The maker of your flux core wire decides what the wire can do.
You may find it jaw-dropping that it’s made to the manufacturers own standards and rules.
But the welding parameters chart sold with the wire should detail what you’re to expect.
And this also means that GS flux core wire is different between each maker’s brand of E71TGS wire to E71TGS wire.
You’ll find there’s no strength testing done or imposed. The strength is whatever the wire manufacturer says.
And you have to take their word for anything else they say the wire does.
Why does the AWS allow this?
Because they don’t want to hold back new wires for flux core welding coming onto the market..
If a manufacturer finds a new kind of flux core wire. And a way of making it that meets a need in the market. They can freely sell it. As long as they tell you what you’re getting.
New wires to the market aren’t then delayed because of testing to a spec. Or because of waiting for the creation of a new AWS spec.
Certified E71T 11 Flux Core Wire
-11 or you may see it on your brand of mild steel flux core wire as E71T11. Is a strict specification by the American Welding Society.
Your welding wire has to go through a panel of tests to prove it meets that standard. And that takes time.
Your flux core wire’s welding performance and strength is fully tested. And the manufacturer has to do this testing before they’re able to use this code on their wires.
Your flux core wire with E71T11 as part of its name has to do multi-pass welding. And perform up to a certain level and give a certain result when making multiple welding passes.
It’s a wire for all positions welding. And again its capabilities are measured.
E71T11 supports spray transfer welding. And the welding polarity is DC – Direct Current.
Don’t worry. Your flux core welder supporting flux core wire takes AC in from your power socket. And converts that to DC so that you can weld flux core.
It’s also safe to assume that your E71T11 wire will perform better on galvanized mild steel.
Netting This Out E71T-11 v E71TGS
E71T-11 flux core wire meets a strict specification. You know what you’re getting.
When you buy E71T-11 from one brand or another you know how the wire will perform.
And it won’t vary much
E71T-GS is a general standard. There is no real specification other than its single pass.
The performance of your E71TGS flux core wire will vary from brand to brand.
It’s up to you to test which GS wire you like. And you can’t expect the same results if you change supplier. This doesn’t mean the wire is no good. It may be great flux core wire.
But it’s up to you to decide.
E71T-GS vs E71T-11 Polarity Used To Weld
E71T-11 needs your MIG gun set to the negative polarity. Flux core only welders will come setup that way.
And for your MIG welder that can also use flux core wire you’ll need to remember to change your polarity over. From positive to negative.
E71T-GS will most likely also use negative polarity. But as there is no standard for polarity with this wire, you can’t be certain.
You should double check this. Check with the manufacturer’s welding parameters chart for your flux core wire.
E71T-11 vs E71T-GS Tensile Strength
The number 7 tells you the ‘up to’ tensile strength number.
What do I mean by up to?
Your E71T-11 flux core wire is tested to. And certified to take 70k pounds per square inch of pressure before it breaks apart.
But your E71T-GS wire is not tested. The 7 in this case is an ‘up to’ number. The tensile strength is anywhere up to 70k pounds per square inch.
And when you look at the specs of the different brands of E71T-GS wires. You’ll find the tensile strength numbers vary wildly.
When the two E71T11 and E71TGS are there side by side at your local welder’s supply.
Or when only E71TGS is available at your local welders supply. Do you hold out and search for some E71T11 flux core wire?
The choice is yours.
Pick the flux core wire with -11 on the end when you want certainty. And know your wire will weld to a standard you expect.
But when you’re looking for something a little different and have the time to check the brand’s spec. And test to see if its what you’re looking for.
The -GS could be for you. Particularly of your -GS wire is cheaper.
About Ben Norton
I learned welding 30 years ago at a local community college. Then learnt how to fabricate and hone my welding working in a workshop. And later in my own company.
I’ve welded projects large and small. Commercially and privately for friends. I MIG and flux core weld but my favorite is TIG welding.
When I’m not working, you’ll find me out and about with my wife and my son. And our two gun dogs. Or at home doing jobs around the yard and feeding the chickens.