Stub axle repair - method and material?

[Bill Edwards]

I've got a repair job where a stub axle has snapped off. It's a rake for rowing up grass, powered by a tractor.

The design of it seems to be to have a piece of plate (approx 10mm thick) welded onto a piece of box section frame. The plate has a hole in and I expect the stub axle was welded from the rear.
It's here that it has snapped, and the rust marks show it's been going for some time.

I'm intending to buy a piece of 25mm round stock, cut off the plate, weld the round stock on from the rear again and weld the plate back on. Or, better yet, if I'm able drill a hole right through the box section and make a better job of it.
What should the steel be for the round stock? Will ordinary stuff suffice, or should it be something like EN16?
If it fell off it wouldn't be dangerous, but naturally I need the job to be right as it's for somebody else. Perhaps anything will be strong enough, but before ordering it would be good to have some thoughts on it.

 

[Paulbarrett]

Can you get a picture up?

 

[Bladevane]

Years ago (that's my disclaimer for any technical inaccuracies) I machined some parts for a local farmer and always went for EN24T although looking in my 1988 Macready's Steel Stock Specifications Handbook I see EN16 is pretty handy stuff with 55 TSI tensile and easily machinable. The downside is that it has a pretty high carbon content of 0.32/0.40 % so there might be issues. Best to check with a welding engineer as it might need PWHT.

 

[printcom]

I had to repair a couple of Tedder shafts last year. I used EN8 and they seem to have held up OK this year.

 

[Bill Edwards]

No pictures unfortunately, I've not managed to get round to replacing the camera - and the machine is some distance away, so it's a matter of getting all the bits, every tool that may be needed, and hoping to be able to complete it all in one go!

 

[Bill Edwards]

I am suspecting that any stuff ought to do, but I'd like to make sure I'm doing the job right.

 

[blenkie1]

I would of thought 25mm mild round would be ok. The wheels will only be down when its in a field and not a lot of weight on them anyhow.

 

[Turbo]

The wheels will only be down when its in a field and not a lot of weight on them anyhow.

It's not the weight on them that would cause the damage. When travelling along a field they will have to withstand a lot of shock loading every time they hit a rut or bump which will be often as fields are not very smooth.

 

[blenkie1]

It's not the weight on them that would cause the damage. When travelling along a field they will have to withstand a lot of shock loading every time they hit a rut or bump which will be often as fields are not very smooth.

Yes I know but my point is they don't need to be anything fancy just ordinary mild steel. Most of my work is agricultural/forestry work and it would just be mild steel I would use. I know what abuse they get.

 

[Bill Edwards]

I've ordered a piece of EN8, my thinking is that it's better than ordinary but not as brittle and easier to weld than EN16, and should be more than up to the job.