TIG filler rod. structural use? heat treating? properties?

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background: I need to fabricate a way to hold small twisted test tubes in a water bath for a toxicity experiment i am running. No airplanes, bridges, submarines or other life or death things. just a rack to hold a science experiment. So feel free to shoot from the hip on this.  think of it like a bunch of little metal tongs holding a kinda heavy series of tubes, nothing more.WHAT IS THE STRUCTURAL INTEGRITY OF FILLER ROD:I need 1/16" stainless round solid round bar. That is really hard to find for some reason. I only need 6" pieces so filler rod is the obvious alternative to buying full sticks of very bendy tooth pick like rod. If i just buy a pound of 1/16" tig 308 filler rod is that the same stuff? Filler rod has not been made with any change in density or flux or anything right? I assume it it not heat treated and the tolerances are not perfect but that is not needed for what i am doing.HEAT TREATING:Lets say i build this apparatus stand/holder using little tongs of 1/16" filler rod. Lets say it isn't quite strong enough, maybe i see some bending. Can i just get all the metal red hot and quench it in cold water? Will that "heat treat" it or is there more to it.
Reply:Interesting. I dint have anything to add that I can count on a fact, but I would think that tig filler is held to a higher standard than say a piece of 2 inch pipe as far as the chemical makeup ofthe steel goes anyway. And seems to me would provide greater accuracy to your test. My question though is how are you going to weld tig rod together? I'm sure guys can do it, but it cannot be an easy task. Wouldn't a SS test tube holder with a handle be easier to design than a tig wire tong holder? If you submurging the test tube, does it matter if it's held by tongs or in a rack? I guess not knowing the whole picture it's hard to see a possible better way. I look forward to seeing what you come up with and what others offer up as help. Not that I am much help. I am only going off whats makes sence to me....Offering CNC Plasma cutting and welding projects.Follow me on facebook https://www.facebook.com/nobigdeal.fabSupport those that support WW.
Reply:I suspect that the filler will be work hardened due to drawing and straightening.  That may make it ultimately a bit "stronger" than "annealed" (heat and quench), but "stiffness" should be the same.  Stainless behaves differently than carbon steel.  You can get larger filler if strength is a concern.  If you want cheaper, just get some 304 stainless steel lock wire."USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:You'll definitely want 316 stainless filler because it has about twice the yield strength as (stiffer than) 304/308/whatever. And no, 300 series stainless cannot be heat treated. I use 1/16" 308L filler at work and it's pretty flimsy, you might wnt to bump it up to 3/32", it's quite a bit more stiff.Welding/Fab Pics: www.UtahWeld.com
Reply:Originally Posted by MikeGyverYou'll definitely want 316 stainless filler because it has about twice the yield strength as (stiffer than) 304/308/whatever. And no, 300 series stainless cannot be heat treated. I use 1/16" 308L filler at work and it's pretty flimsy, you might wnt to bump it up to 3/32", it's quite a bit more stiff.
Reply:Originally Posted by OldendumI suspect that the filler will be work hardened due to drawing and straightening.  That may make it ultimately a bit "stronger" than "annealed" (heat and quench), but "stiffness" should be the same.  Stainless behaves differently than carbon steel.  You can get larger filler if strength is a concern.  If you want cheaper, just get some 304 stainless steel lock wire.
Reply:Originally Posted by NoBigDeal Fab...  I would think that tig filler is held to a higher standard than say a piece of 2 inch pipe as far as the chemical makeup of the steel goes anyway....
Reply:There is not that much difference in yield strength between 304 and 316.  And the Modulus of Elasticity is the same."USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:Originally Posted by OldendumThere is not that much difference in yield strength between 304 and 316.  And the Modulus of Elasticity is the same.
Reply:Just make a sample shape and bend it to test, don't overthink these things. It works or it doesn't!Stronger is better, so if you can use 1/8" do that for increased rigidity. 316 is respectably stiff. We used a lot of it where I worked and bent "stuff" out of it now and then. You aren't going to weaken it for your purpose by bending it. I've folded it tightly against itself making welding curtain hooks. A bench vise, vise-grips, a pair of side cutters, etc are the basics for bending. A bench grinder or an angle grinder with a  1/2" flap disc would do to smooth the cut ends. If you make many pieces, a bending jig could be made to ease the job.Pics of the tubes and related apparatus would help. We aren't mind readers and there may be a MUCH better way to do this!
Reply:You can look up material properties at places like matweb.com or at various companies who produce wire.  Some of the properties will depend on the material condition - annealed vs. drawn/work hardened.  A 1/16" wire will be strong in tension but not stiff."USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:Your other option from 316 is to use 17-4 ss. It can be heat treated, way up the scale to the rockwell 60's and even more. It is magnetic SS, and it would need a polishing to keep it rust resistant, whereas 316 is gonna shine no matter what. 17-4 is very tough material, so if strength/ stiffness is paramount, I would give it the nod rather than 316. (The exception is if you are using it with caustics; if so, then 316 is THE choice.)EDIT; this is post 4130 for me! Seeing as how much I love to work with chromo, I like the irony!!!And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:Originally Posted by RojodiabloThe exception is if you are using it with caustics; if so, then 316 is THE choice.
Reply:Originally Posted by cadmusis 316 more chemical resistant than 304?
Reply:Originally Posted by cadmusohh  ok.  where can i look this stuff up?
Reply:Originally Posted by cadmusis 316 more chemical resistant than 304?