TIG filler ER312 vs ER312H ?

[taylorkh]

Can anyone tell me the difference between these two fillers? If there is in fact a 312H standard.

It is my understanding that H following a TIG number indicates high carbon and L signifies low carbon. I purchased some ER312 filler last year. I was using it yesterday and when I was done I noticed that the 3/32" piece I was using stated 312H. The others in the package were 312. I checked the package of 1/16" which I purchased at the same time. All were marked 312H.

The packages are labeled ER312. The brand is Welders Choice (which does not seem to exist on the net any more). I purchased the filler from use-enco.com (not welding specialists). The enco customer service rep was kind enough to determine that they get the stuff from Welding Material Sales and called them on my behalf. They told the enco rep that ER312 and ER312H are the same. "They are both stainless steel" - not confidence inspiring.

I am not doing any code welding - no nuclear plants or anything like that. I purchased the 312 as I understand it to be good for welding high carbon steel, stainless to carbon steel and other hard to weld situations.

I would be interested to learn if there is really an ER312H filler and what its characteristics are.

TIA,

Ken

[wmgeorge]

Google shows lots of hits for ER312 as > http://www.lincolnelectric.com/en-us...ncolnElectric)

But nothing for ER312H, could be the H stands for Hobart or similar?

[taylorkh]

Thanks wmgeorge. I have done some considerable searching. As you say ER312 is easily found. ER308 and ER317 are available in H and L varieties which I always understood to be High and Low carbon. I need to stop by the local community college and speak with the welding instructor. He has a rather good AWS library and perhaps we can get the answer direct from the source.

As to Hobart... this stuff says Made in India on the package. Not sure if Hobart makes filler there.

Ken

[wmgeorge]

If they are stainless steel rods (TIG) why would they have any carbon let alone high or low?

Went to AWS website and did a search one result, you might get more > http://www.aws.org/w/a/

[Burnt hands]

This is a part from another post on welding 316ti.
316H is mentioned so there appears to be both L and H versions of 316.
Don't know is it carries over to 312.


Stainless Steel - Austenitic - 1.4571 Bar
1.4571 Bar

Stainless steel types 1.4401 and 1.4404 are also known as grades 316 and 316L respectively. Grade 316 is an austenitic grade second only to 304 in commercial importance.
316 stainless steel contains an addition of molybdenum that gives it improved corrosion resistance. This is particularly apparent for pitting and crevice corrosion in chloride environments.
316L, the low carbon version of 316 stainless steel, is immune to grain boundary carbide precipitation (sensitisation). This makes it suited to use in heavy gauge (over about 6mm) welded components.

For elevated temperature applications the high carbon variant, 316H stainless steel and the stabilised grade 316Ti stainless steel should be employed.