Cast welding - failure.....

[Ohio-Rider]

Would you be able to check the hardness of your broken axle? It would be best for me if I knew the rockwell hardness of your present axle. Using the corner of a file see if you can scratch the axle with it. Does it dig into the metal with out much trouble or does it just slide across it?

We may not need to be discussing heat treating methods. There are many differant metals available today that didn't exsist 50yrs ago.

I would venture to assume there is a metal available, suitable to make your axle from without the need of heat treating. We won't know that till we know what the original was made from. Thats always a good starting point.

[indianut]

I would make the hollow axle of High Stress tool steel such as S7 and have it heat treated to the same hardness as the broken one. As for the kickstand I will stand behind brazing as Tried and True for me

[swall]

I am assuming that the axle does not have to act as the inner wheel bearing race, like the front on my '52 Chief. So, here goes. Stressproof would probably be OK. As one of the posters said, it is 1144 steel and it machines well, so you have no trouble cutting the threads. A similar material is Fatigueproof, which is about 20% higher tensile strength than Stressproof. A further upgrade would be Etd 150--it is a special drawn 4140 grade, not heat treated, but has strength close to a grade 8 bolt. It has some has some sulfur/selenium/tellurium additions to enhance machinability. The Rockwell is 32 min on the "C" scale, so a good carbide threading tool will be necessary. None of these are designed to be heat treated, as the final cold drawing process strengthens them beyond what normal hot rolled bar would be. You can get Etd 150 from McMaster-Carr and the Stressproof can be obtained from www.onlinemetals.com. The latter will cut you any length you want. UPS is a killer, though, as they are on the west coast.

[Kojack]

I'd guess that the original axle was made from something like 1020. I filed on one that I have and there's no indication of any hardening. Case hardening is more for abrasion resistance and you don't need that for the axle. Something like 4140 would make a great axle in my opinion. We used to get it quenched and tempered in our shop. I made a couple axles out of it for guys over the years and never had any problems. Of course I made a couple from 1020 also and never had any problems. It sounds like the axle is too small for the loads on it. I guess you're stuck with it unless you want to get into some custom parts. I'd say try the 4140 and save the Evel Knievel stunts for your XR-750. And yes, make sure everything is nice and tight. By the way, when you first mentioned your heating and oil quenching project I didn't realize that it was for the axle.
I'm surprised that Swall found his stand unweldable. I've seen several that have been welded succesfully. I'd planned on welding a new foot on my Chief stand. I'll let you know how that goes. I wonder if the later stands were a different material? Now, Admin said at first that he was repairing his stand but in reality he was repairing the frame casting. I still think that the frame castings are made from some kind of steel but I'm going to check with a couple of guys who do frame repairs just to satisfy my curiosity. There have been a ton of neck castings raked and stick welded over the years with no problems so I kind of doubt the white cast iron theory. Plus, like I mentioned, my 741 Indian frame was tack welded together before it was brazed. They look like plain old arc weld tacks, nothing special.

[swall]

Kojack--it would not surprise me if some frame lugs and necks were steel forgings rather than castings. If so, they would be readily weldable. In the situation with my '52 Chief kickstand, I decided to find out what it was before I attempted to fix it. As it turned out to be malleable cast iron, I knew that brazing would be the best option and that is how I proceeded.

[Tom Lovejoy]

I thought I would make my next one from stressproof - so thats how you spell it :-) I think if I remember right there is plenty of room, thought I would try making it a bit thicker. I bet it would hold up well. I will try it next time I have em off. Thanks for the info guys - kind of interesting stuff.