ACEngineering
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- Location
- Oxon
Should i weld this?
- Thread starter spikeislander
- Start date
Mursal
Member
Yes it is, as the weld will be part of the eye, not just holding it in place, but I see where you're coming from. And the surface area available is very restricted .........
multi power
Member
- Location
- pembrokeshire
But if weld is strong enough to hold the ring into a trailer it's plenty strong enough to build up the drawbar
multi power
Member
- Location
- pembrokeshire
But it hasn't broke yet, building it up will add strength will it not ? It's bound to be made from nice steel, if it was poor quality rubbish it would have broke long ago
spikeislander
Member
- Location
- bedfordshire
In my eyes the strain is "pull" on the pin more than "down" pressure? Hence why alot of drawbars are not rated that high on absolute carry. This wear is more from the two parts turning past each other than the pressure between them, I replace the pin very regularly
NYTP
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- Location
- Market Rasen, Lincs
Unfortunately, we don't have any of these type swinging drawbar in stock used.
MickW
Member
- Location
- South West
It's a drawbar on a big tractor which could go down the road at 40 or 50kph The next thing we will hear is that a trailer has become detached from a tractor, not a problem the tractor owner saved some money because he welded the drawbar.
For me if you need to ask the question you probably know the answer, you and maybe others will live with the consequences
For me if you need to ask the question you probably know the answer, you and maybe others will live with the consequences
not necessarily. welding it can easily affect the parent material from a whole range of factors such as heat or metarlurgical from the filler rod. Either of these could actually cause the welded component to be weaker than currently, even with a greater volume of metal.
Disagree.
tensile load on the drawbar is just down to the tractive effort (or braking or cornering) of the host vehicle against the trailer. the greatest stress will be from the bending stress in the drawbar, followed by the shear stress in the plane through the weld
Go buy a new one, someone else's life is worth it
as I, along with others have already said, welding it up is into dodgy territory but lets say hypothetically speaking if one was to come up with a plan to weld it....
you could get all fancy with pre heating it and going as far as tempering it after, which is an art in itself btw, or you could take the bull by the horns and mig it up.
if i didnt have a way of drilling it out after id get myself a bit of copper rod the size of the pin hole, tap it in and weld her up.
but i wouldn't do it all in one go as too much heat here isnt going to be your friend, too little wouldn't be great either so i might pre heat it slightly and then run my first run of weld round my rod to start building it up, but then id stop and wait a few mins to let it cool back a bit and then id weld again and continue the process.
if i had a mag drill id use the existing hole as a guide and run out the rest.
be the way others would do it but ive found the mig to be a very universal weld thats not too hard and not too soft.
you could hard face it for the last layer but you dont waht to be wearing out the hitch on the machine either.
of course thats all hypothetically speaking so you can take from it what you will.
you could get all fancy with pre heating it and going as far as tempering it after, which is an art in itself btw, or you could take the bull by the horns and mig it up.
if i didnt have a way of drilling it out after id get myself a bit of copper rod the size of the pin hole, tap it in and weld her up.
but i wouldn't do it all in one go as too much heat here isnt going to be your friend, too little wouldn't be great either so i might pre heat it slightly and then run my first run of weld round my rod to start building it up, but then id stop and wait a few mins to let it cool back a bit and then id weld again and continue the process.
if i had a mag drill id use the existing hole as a guide and run out the rest.
be the way others would do it but ive found the mig to be a very universal weld thats not too hard and not too soft.
you could hard face it for the last layer but you dont waht to be wearing out the hitch on the machine either.
of course thats all hypothetically speaking so you can take from it what you will.
spikeislander
Member
- Location
- bedfordshire
I'll probably end up wearing this a bit more then getting a new one. But if Ive pulled a 7 leg subsoiler all day right in bringing 350 hp to its knees is it likely to break going down the road folded up on two tyres pulling it home killing some people.
IMO yes it could.
during the field work, the load is mostly tensile from the tractor pulling, with some tongue load at relatively low speed, so dynamic effects wont be as significant.
On the road, you wont have the tensile load int he direction of the tractor to the same extent, but the dynamic loads on the drawbar from the tongue load could (and will) be significantly higher than those experienced in the field.
If it were to break, i would expect the fracture face to be vertically, near the pin, where the load area is least
How about grinding/cutting the high part down to the same as the lowest part. Then tack welding a plate on it?
It'll still be as strong as now, but will simply wear the plate.
multi power
Member
- Location
- pembrokeshire
That's REALLY simple, whatever rods happen to be in the box
Hypothetically with mig being a low hydrogen process then opt for e7018 low hydrogen electrodes.........
sorry mursal for not replying til now, ive been researching something for the last few nights so i didnt get a chance to reply but i see Aj beat me to it with an answer.
the first two numbers denote the tensile strength of the arc rods.
despite what a lot of the old guard would say about mig welding, your common garden 6013 rod is about 60,000psi tensile strength, the mig weld is approx 70,000psi and the 7018 LH would be 70,000psi so the mig and the 7018 would be very similar, of course the mig is way easier just.
the 7018 would be similar but the drawback is making sure you have all the flux out before the next weld, and 7018's dont like giving that up easily so if it was me id dress each run slightly with the grinder as id go, just to make sure everything was clean before the next weld so as to avoid stress points.
id also use a rough file to re point the rod for an easier start again as the low hydrogen burn concave compared to the convex shape of the 6013 say.
most peck the rod at the work piece to restsrt it but this can break off lumps of flux and i find that in turn will leave a slag hole in the weld as you start.
if i wanted to get pedantic about it id be inclined to maybe go with a 7015 or a 7016 maybe, iirc more designed for a better penetration of higher tensile steels and with somewhat less slag to get shot of but as im no aficionado on welding or a Jodie either, im just going off the bit of knowledge i do have.
Damian ,have you welded it up yet . Jfdi then find some polyurethane ,try a worn boom pad out of forks if room for it ...and make a wear pad or a steel plate in and pipe a dribbler to it
Hard to say from the pic, but it looks to have worn almost half way through.
The time for building up with weld / washers has long since passed surely ?
I'd risk welding it up if used just for field work. But out on public roads ?
Your call.
The time for building up with weld / washers has long since passed surely ?
I'd risk welding it up if used just for field work. But out on public roads ?
Your call.
yep, as i was saying, hypothetically speaking...
but, im wondering about something now.
what weight is a drawbar rated to dose anyone know.
the hitch is 3 Tonne odd so whats a drawbar?
if the hitch is good for 3 tonne than it id be tested to 5 or more id imagine, so whatever the working load of a drawbar is it cant be too much for id imagine you wouldnt get to put 5 tonne on it for too long.
so could we guess that its maybe 2T, and could one assume the load test would be pushing down on the jaw on one side and the other end would be wedged in something the same as the hitch mount so as to test it similar to working conditions.
im just rambling here but the more i think about it the more im convincing myself that welding up the eye area that's worn isnt really going to afect the safety of the hitch as even if its welded its not going to alter the hitch too much structurally, if you weld it up then even if it might weaken it slightly, and I cant even really say if that would happen or not as im not a metallurgist but even if it did, the repair would probably negate that anyways.
if you really wanted to be pedantic about it then you could get it load tested, any chain and lift retailer crowd will be able to give it some form of a test and cert it id imagine.
so as much as i was originally against the idea, like a few others too, im starting to think its a safe enough repair.
think about what im saying there, have i a point?.