View Full Version : TIG welding 8620

12-16-2002, 11:40 AM
I need to weld some 8620 steel parts, not sure what to use as fill rod. Mabey I should just use 8620, but I can't find any fill rod called "8620"
The work will have to be case hardened after welding and machining is completed.


12-16-2002, 12:04 PM
8620 is a casehardening grade as you probably know. It has good physical properties, as in tensile strenth. It welds up great, don't have to worry about underbead cracking and such. I've used a lot of it for parts that needed to be welded on and needed high tensile strenth.

Answering your question, personally I don't know of a filler rod which would have as high a tensile strenth and not be affected by the casehardening and quench the same as the 8620 would be. There might be such an animal, but I've never ran across it. Using 8620 as the filler would be the smartest thing in my opinion. There will be some grain growth problems as there is with any welding process.

What shape is the material you have on hand. If flat you can saw out some strips and use these as filler, even small diameter round can be split to get down to size, fire up the forge and pound some out. Bailing wire would work, but the weld wouldn't have the 100,000+ psi tensile strenth that 8620 does.

How strong does the joint have to be?

Sounds like a lot of work, hope some other has some info for you. Good luck with the project.

12-16-2002, 07:16 PM
I like the idea of using parent material as filler rod.
A little off thread . . . but I'm looking for a TIG welder./ . . Have looked at Miller Lincoln Hobart all in the $1200 to $1400 range. Anyone have any pros or cons ? I have never TiG welded and its rather hard to evaluate the features from the mfg's printed materials

12-16-2002, 10:42 PM
Two things to consider before the power supply is the gas flow regulator (a plain regulator will just cost you more gas than it should) and the cable/gun. Then buy a Power block with what you have left.

I prefer the air-cooled guns, but that is just me. If you have running water and a drain, you can use that for a water cooled gun. Or you can set up a coolant system. I also prefer an Alan Bradley Aluminum foot switch.

Check with your welding distributor, they may have package deals.

I have used Miller for 28+ years and prefer them. Every Hobart I have seen is an enormous PIG - more for pipeline work. Lincoln Electric makes good stuff - or did.

Paul Gauthier
12-17-2002, 06:26 AM

I use a Miller econotig, have had for about 6 years or so and have been happy with it.

Paul G.

Paul H
12-17-2002, 06:20 PM
They only downside of the "econo" TIG units is their low current circuits down go down low enough to weld thin stuff. If you won't be welding under 1/16", it's not an issue, but if you want to be able to work on thin stuff, then you'll have to fork up a couple more $'s. Miller offers a syncrowave 185 that seems to bridge the gap of a full range machine, without the full range price of larger units.

Air cooled torches work fine for lower amperage, but the torch bodies are larger. There are some amazingly small water cooled torchs that allow you to get the torch into some really tight corners.

Rob Frink
12-17-2002, 07:42 PM

I have an ESAB multimaster 260. It is MIG and TIG...and of course stick.

It replaced my old 1965 Westinghouse TIG dinosaur that weighed a bazillion lbs.

I've had the ESAB for about 2-1/2years now and simply can't say enough about it....or the great service from the ESAB folks. You can check them out online....search for the Multimaster 260.



[This message has been edited by Rob Frink (edited 12-17-2002).]

12-19-2002, 05:18 PM
ER80-2 or ER70-2 would be your best bet.They would both give you the weld properties you are looking for.I would go with the 80 series because it's material make-up is alot closer to 8620.You can pick these up at just about any welding supply store.