Welding harden pins?

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I've noticed that welds don't stick to harden pins very well can something be done to get it to weld like heat it or something?i have a draw pin that needs to be extended 3" to work better i have a piece of mild steel but trying to weld it don't like sticking to the harden pin side,i'd just buy a new longer one the the price is nuts.any tips?HOBART IronMan 230 MIGSmith Lifetime WH200 HD O/A Torch
Reply:Go to Enco and buy a piece of water hardening steel rod, it is material similar to a good screw driver material, after you slowly heat and quench it in water. Then just make your own pin. They will have it to you in a day or two. Even if you did not harden it, it is very hard. But you can drill it, for a chain to keep it near or a cable. Or a roll pin handle or something like that. I would not trust a weld on hardened material though. How big is it, could you find a common bolt and use a portion of the bolt instead?        Sincerely,             William McCormick
Reply:Thanks will it's a 3" pin,can't i just do something with my pin heat and quench with water say just the end of it?HOBART IronMan 230 MIGSmith Lifetime WH200 HD O/A Torch
Reply:Originally Posted by damanThanks will it's a 3" pin,can't i just do something with my pin heat and quench with water say just the end of it?
Reply:I have heard of guys putting hardened shafts in asbestos blankets to soften them, so they could machine them. But I heard that even then it was negligible, it depended on what type of hardening it was. And what type of material it was. There is case hardening and full hardening. Case hardening you might stand a chance. You can case harden mild steel. But you can also case harden oil hardening material and air hardening material.A drill bit is an example of case hardening at the shaft where you put it into the chuck. You can still machine that shaft to turn it down to a smaller shaft. You have to skim off the case hardening though. But you cannot turn down the rest of the drill bit where it is fully hardened, through and through. If it is full hardening like for leaf springs and oil hardening or air hardening material, you are through, you are not going to get a soft metal anymore. But when all is said and done, if the material is high carbon you are not going to get a good weld, without preheating and slow cooling, because the material next to the weld will super harden, unless it is just case hardened. I have even seen where brazing was done on hardened metal, and the hardened metal cracked right next to the braze, because it got so hard. Are you saying three inches long or three inches in diameter.Anything that requires a three inch diameter pin, you better just get a new piece of material. You might be able to find someone with a piece of stainless steel three inches in diameter, laying around. I know we used to have some, and guys from the elevator company would come in to get a three foot piece to make bullets to drop down the elevator piston shaft. To clear out debris. The guy got a hernia lifting it. Wow is that stuff heavy. You could if you wanted just heat the surface of the stainless pin and believe me nothing is going to hurt that surface. But it might cut right through hardened tool steel. Ha-ha. Sorry I have no real happy news for you.        Sincerely,             William McCormick
Reply:No thats fine will, it really is not that big of deal if i can't weld to it i'll just have to get a new pin i just thought there would have been a way to soften the harden pin end so i  could weld it,it's three inches in diameter a common farm implement draw pin and i need to add to it about 3".HOBART IronMan 230 MIGSmith Lifetime WH200 HD O/A Torch
Reply:Sure you can soften hardened carbon/alloy/tool steel.  It's called annealing.   But if you want or need the pin to be hard after you do 'whatever' to it, then you would have to harden it again.  Which means the full time and temperature control, with heat soaks at the proper time and temp, and then quenching in the appropriate media at the appropriate cooling rate, and then most likely tempering it at the again appropriate time and temperature.  And then possible finish machining (grinding with fine grit most likely if it is a machine pin).And welding a hardenable steel is NOT the same as welding plain low carbon steel.  As you found out.It's not that you are trying to weld something that is hard, but that you are welding a steel that is hardenable with medium/high carbon and/or other alloying elements.  So once the heat of welding gets the piece of hardenable steel all hot, it can and often will get HARD.  So hard that the thermal gradient from weld to not weld causes the now HARD steel to crack.So, short answer:Do not weld a hardened steel pin.Just go buy the appropriate length already hardened and machined steel pin.And I would kind of suggest getting O1 oil-hardening steel instead of W1 water-hardening.  Or go all the way to A2 air-hardening.  But with any of those, you still sort of have to watch the time and temperature or the heating and quenching and then the subsequent tempering.  And again, the possible need for finish grinding to true the OD of a pin after heat treatment distortion depending on the dimensional tolerances needed.Usually easier and cheaper and faster to just buy the right pin.  Unless you have the equipment and knowledge to heat treat your own pin.  Small diameter drill rod is one thing, big diameter drill rod/pins is a bit bigger task.  The best laid schemes ... Gang oft agley ...
Reply:No the pin doesn't need to be re hardened after,it just happens to be a harden pin thats used in the application is all.HOBART IronMan 230 MIGSmith Lifetime WH200 HD O/A Torch
Reply:agri supply has pins pretty inexpensively up to about 7 in long.
Reply:I thought for sure I could find a 3" bolt around. But no good, I could not find one. And I don't want to bother my friend, unless you think a bolt would solve your problem. Then I would call him. He gets me any stainless steel stuff I need. And he supplies the giant bolts for bridges and construction. How long does it need to be?       Sincerely,             William McCormick
Reply:Originally Posted by William McCormick JrI thought for sure I could find a 3" bolt around. But no good, I could not find one. And I don't want to bother my friend, unless you think a bolt would solve your problem. Then I would call him. He gets me any stainless steel stuff I need. And he supplies the giant bolts for bridges and construction. How long does it need to be?       Sincerely,             William McCormick
Reply:Originally Posted by damanNo the pin doesn't need to be re hardened after,it just happens to be a harden pin thats used in the application is all.