Tig parameters chart

[Miller13]

New owner of a Kemppi Minarctig evo 200 and looking to get a leg up on the amps/rod/filler/flow parameters at various plate thicknesses. I did come across the DIY guide here on this site, but it only goes up to 3mm. So I extrapolated for the rest. Does this look like a decent starting point for mild steel?

Also, this is a home game and it helps to have the consumables (tungsten, filler rod etc) cover as wide a range as possible.

 

[Tangledfeet]

I've seen the nominal 30A/mm, plus or minus ten percent depending on type of joint, elsewhere too - a This Old Tony video if I recall.

 

[addjunkie]

https://www.millerwelds.com/resources/weld-setting-calculators/tig-welding-calculator

Have a play here, all imperial, but easy enough to convert

 

[Miller13]

Ok, so it looks good by the 30A/mm rule.

As for the millerwelds calculator, they say 225-300 amp for 6.3mm plate. R-tech say 7mm in one pass for their 200 amp DC tig. So either millerwelds calculator is textbook/academic (and we're hands-on folk here), or R-tech is a bit too optimistic about their machine.

 

[malcolm]

Ok, so it looks good by the 30A/mm rule.

As for the millerwelds calculator, they say 225-300 amp for 6.3mm plate. R-tech say 7mm in one pass for their 200 amp DC tig. So either millerwelds calculator is textbook/academic (and we're hands-on folk here), or R-tech is a bit too optimistic about their machine.

What are you up to? TIG is not normally best suited to heavier work unless you have all day and want to weld nuclear power stations together. Most would switch the machine to arc before they get to 3mm.

 

[ronan]

What are you up to? TIG is not normally best suited to heavier work unless you have all day and want to weld nuclear power stations together. Most would switch the machine to arc before they get to 3mm.

I had a couple of weeks work welding 3mm thick steel boxes up, i sticked them from the start, wouldn't even consider firing up the tig for them.

 

[Miller13]

What are you up to? TIG is not normally best suited to heavier work unless you have all day and want to weld nuclear power stations together. Most would switch the machine to arc before they get to 3mm.

You're being presumptuous fella. There's nothing inherently wrong with tigging quarter inch plate, it's just a matter of personal choice. Maybe it's my only machine, maybe I hate stick, maybe I want to experiment with it. I could give you a dozen potential reasons of why somebody might want to choose tig over mig/stick for thick plate.

 

[Richard.]

Tig is predominantly a thin gage fabrication process or used on full penetration joints where the defect level of acceptance is so stringent that the tig process is required from a quality POV. Either way it’s very uncommon for DC tigs to break into 150 amps tops.
Malcolm actually made a very valid point he just missed off the reasons why.
Ok so we all know that MMA and GMAW are quicker processes more suited practically to thicker material but they are suited mechanically better as well. DC tig welding a 6mm plus plate is not only the worst process from a distortion POV but also from a heat input POV.
No one is denying that it can’t stick it together and it will do that just fine but it’s far from the best process if you’ve got MMA on the same box. You can use lower currents and higher travel speeds to improve your distortion and mechanical properties in the joint with a much more suitable process not to mention save a lot of time.
I can only think of 1 reasonable reason why someone would use tig over MMA on 1/4” plate and that’s spatter.
If you’ve got a dozen of good reasons I’m listening as I really don’t and trust me I always prefer to tig weld.
A DC TIG amp guide up to 3/4mm is plenty for 99% of situations.

 

[Miller13]

You people don't get it. I am not a commercial enterprise. I do it in my own workshop, working on my personal projects. And yes, I do have all day. Whether stick or mig is more efficient, that is completely irrelevant to me. Whether it's 'uncommon' for DC tigs to break 150 amps, again, totally irrelevant. Whether all this sounds reasonable to you or anybody else on this forum, totally irrelevant again. I did not come here to ask for your opinion on whether I should tig weld 1/4 plate. That's a given. So present your thoughts respectfully, and I shall gladly reciprocate. Don't shove your 'wisdom' down my throat, especially when you're beside the point.

@ Richard. Are you trying to say tig is an overall inferior process compared to mig and stick for 6mm steel? That is really the gist of your post: 'inferior mechanical properties in the joint'. As a sweeping statement, it's complete BS. Maybe that's not what you meant, but then you need to qualify your statements. Say it requires more than one pass for a reliable joint, and I might agree with you. But as it stands, your post can't be taken seriously.

 

[Jim Davey]

There’s a lot of personal opinion involved but what is often referred to as the “best” way to weld something is the method that achieves a satisfactory result across a number of areas, speed, appearance, difficulty, distortion and necessity. If, a perfectly acceptable result can be had using a faster, cheaper process then that is often the way to go.
You can obviously do what you want, it’s your project and your shop, but I think the gist is that as time is a finite resource, you are probably wasting it unnecessarily welding steel above 3-4mm thick with a Tig machine if you really don’t have to.

 

[Richard.]

@ Richard. Are you trying to say tig is an overall inferior process compared to mig and stick for 6mm steel? That is really the gist of your post: 'inferior mechanical properties in the joint'. As a sweeping statement, it's complete BS. Maybe that's not what you meant, but then you need to qualify your statements. Say it requires more than one pass for a reliable joint, and I might agree with you. But as it stands, your post can't be taken seriously.

I don’t think there needs to be so much hostility in your reply. My post certainly wasn’t bashing you, just relaying the reasons why tig guides tend to stop at lower gages.
Call it BS all you want but it’s actual fact that TIG generates more heat input simply because of the reduced travel speeds.
Multiple passes or not if you do a simple heat input calculation for a given tig condition on 6mm you will see it’s a good lump higher than stick/mig. So yes mechanically it’s toughness values will be lower and distortion control will require a lot more thought.

If you personally want to use it for thicker gages go right ahead, I’m sure it will be fine for your purposes I was simply giving you some valid points as to why the tig guide stopped where it did.

Now Whether you like it or not My suggestion is you change the way you speak to people on here or find another forum!!!
None of the replies to your thread were in anyway abusing or rude to you or your post, mine included.

 

[malcolm]

I'm sorry my input was not useful and I apologise for being presumptuous. Actually I didn't really think you were welding a nuclear power station together and I'm with Richard on the rudeness.

The TIG amp chart was put together by Paul and myself based on what worked. Extrapolate it how you like but right now you are trusting your faith to Excel. Tried it myself and came to the same wrong answer.

For the right answer the clues are above. Less rudeness and we might have been inclined to help.

 

[Miller13]

Hey Malcolm, stop being a smart-a*se. That's what started this in the first place.

As for Richard, he chimed in to prop Malcolm and put his foot in it in the process. Half of his post states the obvious, as if I ever argued it. Classic straw man argument. Yes, we all know TIG is not normally used for thick plate, for all the reasons everybody mentioned. And then proceeds to call TIG an inferior welding process from a mechanical point of view. It might be slow and fiddly, and might require multiple passes above a certain plate thickness, but mechanically inferior is NOT. Read the paper below, tests done on 6mm stainless 202 show TIG as superior in maximum hardness, yield strength, ultimate tensile strength, the lot. I couldn't find anything like that for mild steel, but every informal/anecdotal evidence I have found suggests a similar result.

I'm happy to call this banter, difference of opinion, small misunderstanding amongst like-minded people. Water under the bridge. At the end of the day, we're all here cause we enjoy a good weld. That table is not just for me, but for everyone who comes across this thread looking for the same thing. It occurred to me it's a little low on tungsten and filler diameter on the bottom side, but I can't seem to be able to edit it. It should be more like 3mm for tungsten and filler for the 6mm plate, and 2.4mm for the 4-5mm plate.

TIG vs MIG on 6mm stainless

 

[rtbcomp]

@Miller13 You have a PM

 

[Richard.]

Hey Malcolm, stop being a smart-a*se. That's what started this in the first place.

As for Richard, he chimed in to prop Malcolm and put his foot in it in the process. Half of his post states the obvious, as if I ever argued it. Classic straw man argument. Yes, we all know TIG is not normally used for thick plate, for all the reasons everybody mentioned. And then proceeds to call TIG an inferior welding process from a mechanical point of view. It might be slow and fiddly, and might require multiple passes above a certain plate thickness, but mechanically inferior is NOT. Read the paper below, tests done on 6mm stainless 202 show TIG as superior in maximum hardness, yield strength, ultimate tensile strength, the lot. I couldn't find anything like that for mild steel, but every informal/anecdotal evidence I have found suggests a similar result.

I'm happy to call this banter, difference of opinion, small misunderstanding amongst like-minded people. Water under the bridge. At the end of the day, we're all here cause we enjoy a good weld. That table is not just for me, but for everyone who comes across this thread looking for the same thing. It occurred to me it's a little low on tungsten and filler diameter on the bottom side, but I can't seem to be able to edit it. It should be more like 3mm for tungsten and filler for the 6mm plate, and 2.4mm for the 4-5mm plate.

TIG vs MIG on 6mm stainless

I think you need to understand heat input effects before throwing out links with no relation to what I’m talking about.
Hardness of weld material????
Strength????
Heat input control is about avoiding grain growth which has a dramatic effect on impact toughness. (Charpys) are the tests you want to be looking for.
Here is a ‘legitimate’ link explaining heat input and it’s importance. to help you out. I believe the simple formula is wrote in there too so you can work some out for yourself. FYI if you do decide to try some out the correction factor for TIG is 0.8 I don’t think it’s mentioned in there but you’ll need it to be accurate
https://www.google.com/url?sa=t&sou...aterials.cfm&usg=AOvVaw3rfYSAoXciWxBjZn7UJpgZ
It’s getting really silly and childish now.
Your not going to last 5 mins here with a major chip on your shoulder like that. Nobody will give you the time of day.
Makes no sense whatsoever as to why you get so aggravated over a couple of harmless posts directly related to your initial post and thread title.

 

[Miller13]

I had a quick chat with Roger, and I've been advised to lay off the attitude towards people who are trying to help. Upon reflection, I think it's time for me to move on. I don't deny the attitude, but whether it's warranted or not, that's a whole different thing.

 

[Richard.]

I had a quick chat with Roger, and I've been advised to lay off the attitude towards people who are trying to help. Upon reflection, I think it's time for me to move on. I've been helped quite enough.

You don’t need to move on it can still be an interesting discussion topic, nobody is trying to attack you and disagreeing with people is perfectly alright if done respectfully.
If I was to make any changes to the extension of the chart I’d increase the amps for the fillet joint but I’d actually do this throughout the whole chart.
I’d also increase the filler diameter on the last two to 2.4 which you did mention yourself.
I never change the Gas flow with current I use 6-7lpm for every gage and just increase post flow times.
The guide is aimed at beginners mind so a regular Tig welder would likely run hotter anyway to go faster.
It’s all in the range mind and subtle differences are generally down to people’s preference rather than musts.

 

[Miller13]

Is there any way to edit that post/chart? I'd rather not leave it big at the top of the page with errors in it. It was drafted quickly for discussion.

 

[carbon]

You need the help from a moderator to edit it now

 

[rtbcomp]

Is there any way to edit that post/chart? I'd rather not leave it big at the top of the page with errors in it. It was drafted quickly for discussion.

If you send me the correct version in a PM I can fix it for you, but it might cause confusion editing a chart that people have already commented on. A better idea may be just to post the new version, explaining the alterations.