Broken drawbar... chances a 'pro' welder can fix it

[Shaneard]

Ok maybe 'snapped' is a better word than shattered. A critical component like that should deform if overloaded, not snap suddenly.

I would say they are hard for a reason. If you hook something to a drawbar, i.e. a baler or hare etc. they would suffer a lot of wear if not hard. I have a friend whom has a 100hp Case tractor and he brought his drawbar to the machine shop I work in one day and ask me to open the hole up for him just a little bit to put a larger pin in for his new no till. I couldn't scratch it because it was so hard and we have the good stuff at work, not cheap tooling.

 

[dragoneggs]

It "yielded". Kinda stretched, like plastic. Not shattered.

Technically it did yield. The point some such as myself are making is that there appears to be little strain after the yield point meaning the 'plastic' zone (between yield and ultimate strength) appears very small and characteristic of hard materials.

 

[muddstopper]

One thing a few are not considering. It broke right at the hole in the middle. Once you drill a hole in it, it loss a large amount of its strength. Not that much metal on either side of the hole to hold anything.

 

[Sodo]

Kinda looks like it was violently torn off. I'd centerpunch it, and compare to normal mild steel. Then if it seems harder than mild steel, try to drill a test hole in it. And if not easy to drill, do the spark test. Try to guess the material.

Somebody better get welding soon or TBNs gonna go nuts! :laughing:

 

[GLyford]

I don't see anyone having made this point:

You don't need to buy a new welder just for this, the AC tombstone buzzbox will do it.

But trying it with regular 7018 will be annoying.

For use with an AC buzzbox, there is an AC version of this rod, sometimes labelled either AC7018 or 7018-AC. Get some and practice. It's actually a pretty easy rod to run.

For critical welds, it is best to use from a freshly opened new package (so you don't have to play around with rod ovens and such). So if you think it might take you 3 lbs. to do the weld, you are better of buying a handful of 1 lb. packages than one 5 lb. box...

 

[bigdeano]

I bought a sealed package of Lincoln 7018-AC from Lowes. I get porosity, especially at the start of a new rod. It helps if I hold a very short arc. I started to burn the first inch of rod on a piece of scrap. It seems to be very similar to 7014 once I did that. I don't know if this is common with 7018. I thought it might help the OP to mention it.

 

[muddstopper]

Kinda looks like it was violently torn off. I'd centerpunch it, and compare to normal mild steel. Then if it seems harder than mild steel, try to drill a test hole in it. And if not easy to drill, do the spark test. Try to guess the material.

Somebody better get welding soon or TBNs gonna go nuts! :laughing:

I havent ever used a drawbar on a tractor to pull anything that I can remember, but I aint a farmer so what do I know. I have seen plenty of metal broken like this draw bar. All these suggestions that its a special harden steel may be right, but I have seen similar breaks on just mild steel. The big hole in the end seems wollered somewhat so I am thinking the steel cant be all that hard. Even tho the metal is 1 1/4 in thick, there is a hole drilled right in the middle of the break. It lost half its strength with that hole. Couple that with the sudden shock of the plow catching in the side of the ditch, the piece just pulled apart, which is why it isnt bent. I am just using the hillbilly logic of a person that has actually broken an anvil. For me, I wouldnt even worry about what kind if steel it is. Grind it, slug plug that hole and weld the heck out of it. If it holds, well and good, if it breaks, then your no worse off than you where before. If you cant get it done local, send it to me and I''ll weld it for you.

 

[k0ua]

I havent ever used a drawbar on a tractor to pull anything that I can remember, but I aint a farmer so what do I know. I have seen plenty of metal broken like this draw bar. All these suggestions that its a special harden steel may be right, but I have seen similar breaks on just mild steel. The big hole in the end seems wollered somewhat so I am thinking the steel cant be all that hard. Even tho the metal is 1 1/4 in thick, there is a hole drilled right in the middle of the break. It lost half its strength with that hole. Couple that with the sudden shock of the plow catching in the side of the ditch, the piece just pulled apart, which is why it isnt bent. I am just using the hillbilly logic of a person that has actually broken an anvil. For me, I wouldnt even worry about what kind if steel it is. Grind it, slug plug that hole and weld the heck out of it. If it holds, well and good, if it breaks, then your no worse off than you where before. If you cant get it done local, send it to me and I''ll weld it for you.

I am thinking the same thing.. and If you send it to me I will weld it with some 7018 for $50 and you pay return postage. I just don't think this is a big deal at all, I would have already welded and ground it smooth and had green paint on it by now.

 

[dragoneggs]

I am thinking the same thing.. and If you send it to me I will weld it with some 7018 for $50 and you pay return postage. I just don't think this is a big deal at all, I would have already welded and ground it smooth and had green paint on it by now.

I agree with you... should be welded and stressed again already! Still fun to analyze though.

 

[ovrszd]

And if the hole isn't needed, I'd weld it full as well.